Thanks, Mariner, and welcome, everyone. Picking up where Mariner left off in this discussion of the balance sheet, the increase in our balance sheet from $12.4 billion to $13.5 billion was driven primarily by deposit growth. As you know, we typically experience a seasonal influx of public funds in the fourth quarter, which started approximately $200 million higher than last year. These balances currently are about $140 million higher than historical levels.
The rate environment and less attractive yield opportunities have resulted in additional funds remaining in deposit [indiscernible] accounts. When combined with increases in deposits from other funding sources, average deposits had increased 13.5% at year end. Non-interest bearing deposits comprise nearly 39% of our total deposits, which puts us in the top 3% of the industry according to SNL Financial.
Our high percentage of free funds is a competitive advantage and is reflected in our low overall cost of funds which was 0.32% for the fourth quarter and 0.35% for the year. This advantage will be even more important when rates begin to rise. Allowance for loan losses is $72 million and allowances as a percent of total loans is now 1.45% compared to 1.61% a year ago. Our allowance for loan loss coverage is more than 2.5x the amount of non-performing loans while the median industry allowance reported for the third quarter would cover just over half of non-performing loans.
During 2011 we had gains on the sale of investment securities of $16.1 million. We harvest gains as part of our overall intentional approach to manage the investment portfolio when interest rates in the economy make this a prudent decision. Through gains we're able to offset lower margin associated with holding shorter-duration securities. In effect, we trade one type of risk for another by supplementing what we lose in net interest margin with gains.
The average balance in our investment portfolio increased 13.8% to $5.8 billion, and activity during the fourth quarter included the roll-off of $335 million in core portfolio securities at an average yield of 2.62%. In turn, we purchased $688 million of securities at an average yield of 1.72%. These purchases shortened the portfolio duration slightly. The average life is now 28.17 months down from 33.8 months in the third quarter 2011.
Over the next 3 months, $410 million of core investments with an average yield of 2.27% will mature. Over the next 12 months, $1.4 billion of core investments with an average yield of 2.45% will mature. Additionally, 73% of our total loan portfolio is expected to reprice or mature in the next 12 months.
As we’ve discussed previously, the components of our capital have shifted slightly impacted by our acquisitions, with goodwill and intangibles increasing relative to Tier 1 capital. We remain well capitalized with Tier 1, leverage and total risk-based capital ratios of 11.2%, 6.71%, and 12.2%, respectively.
Average shareholder equity was $1.2 billion, a 12.3% increase. Since the beginning of 2008, equity has increased by 33.7%. We have grown equity without any dilutive capital actions, and we’ve been able to deploy it effectively to make acquisitions. Further, total shareholder returns since year-end 2006 to year-end 2011 was 11.4%. For the same period returns from the S&P 500 and SNL US Bank Index were negative 1.6% and 69.1%, respectively.
Reviewing other financial highlights. Return on average assets was 0.74% for the quarter, up from 0.65% in the fourth quarter 2010. For the full year 2011, return on average assets improved from 0.82% in 2010 to 0.86% in 2011. Return on average equity for the fourth quarter was 7.83%, an increase from 6.92% a year ago. For the full year, return on average equity was 9.35%.
Turning to the income statement for the fourth quarter 2011. Net income was $23.3 million or $0.58 per diluted share. Total revenue increased 2.2% to $177.3 million for the quarter. Net interest income for the quarter was virtually unchanged, up 1% to $79.5 million. Although average earning assets increased by 8.8%, the changing mix resulted in a lower overall yield of 3.11% versus 3.42% for the fourth quarter 2010. Average net interest margin for the quarter decreased 21 basis points to 2.91%.
For the year ended December 21 2011, net income was $106.5 million or $2.64 per diluted share. Total revenue increased 9% to $731.3 million for the year. Net interest income for 2011 was up slightly to $317 million compared to $310.6 million in 2010. Average net interest margin for the year decreased 27 basis points to 2.94%.
Provision expense decreased by $2.4 million or 32.4% compared to the fourth quarter 2010. For the full year, provision was 30% or $9.3 million lower than 2010. As we’ve discussed in several prior quarters' calls our provision expense is a reflection of our consistent methodology, which considers the inherent risk in our loan portfolio as well as other qualitative factors.
As Mariner mentioned, non-interest income increased 3.2% to $97.8 million comparing favorably to $94.8 million for the fourth quarter 2010. The increase in non-interest income was driven largely by a 10.3% increase in trust and securities processing revenue, which for the quarter was $51.1 million compared to $46.3 million for the fourth quarter 2010. Within this category advisory fee income from the Scout Funds increased 8.6% to $15.1 million, fund accounting and administration income increased 4.2% to $17 million, and income from personal and institutional wealth management increased 50% to $8 million.
For the year, total non-interest income increased by 15% driven by a 30% increase in trust and securities processing. Partly offsetting this increase in trust and securities processing revenue for the fourth quarter was a 9.5% decrease in bank card fees related primarily to debit interchange rules which went into effect in October. For the full year 2011, we reported a 9.1% increase in bank card fees. Peter will discuss the details of our interchange fees and full impact from the Durbin Amendment later in the call.
Although total deposit service charges increased by 7.3% in the fourth quarter 2011, mostly due to deposit growth, consumer NSF OD income was 3% lower than a year ago. The full year impact of the reduction in consumer NSF OD income was 6.5% or 33% resulting in a 3.8% decrease in total deposit service charges for the year despite the year-over-year growth in deposits.
As a reminder, Reg E went into effect in July 2010. As Mariner discussed earlier, we continue to focus on achieving operating leverage. However, as a growth company we continue to make investments, which increases non-interest expense while the corresponding increase in revenue should follow in subsequent periods. For the fourth quarter, non-interest expense increased by 2.7% compared to the fourth quarter 2010, and for the full year expenses were up 9.8%.
I want to point out an acquisition-related item that impacts our expenses. As a reminder, we have earn-out agreements on many of our larger acquisitions. Accounting standards require that we review and potentially adjust our liabilities related to these earn-out payments. As you may know, there are 2 variables that affect these adjustments: one, the recalculation of liabilities using actual results instead of estimates; and two, expected future performance.
In 2011 the total impact of this adjustment was a charge of $2.6 million with $1.7 million taking place in the fourth quarter. Earn-out liabilities are analyzed on a quarterly basis, and you should expect to have future adjustments either up or down throughout the earn-out period. With that, I’ll turn the call over to Peter to discuss the business drivers behind this quarter’s results.