The following table sets forth information relating to average balances of interest-earning assets and  interest-bearing liabilities for the years ended December 31, 2012, 2011 and 2010. Average balances are derived  from daily average balances. Non-accrual loans were included in the computation of average balances but have been  reflected in the table as loans carrying a zero yield. The yields set forth in the table below include the effect of  deferred fees, discounts and premiums that are amortized or accreted to interest income or interest expense. This  table reflects the average yields on assets and average costs of liabilities for the periods indicated (derived by  dividing income or expense by the monthly average balance of assets or liabilities, respectively) as well as the "net  interest margin" (which reflects the effect of the net earnings balance) for the periods shown.  Average  balance Interest Yield/  cost Average  balance Interest Yield/  cost Average  balance Interest Yield/  cost (Dollars in thousands) Interest bearing deposits at banks 11,927 $ 27 $ 0.23% 3,295 $ 4 $ 0.12% 5,286 $ 8 $ 0.15% Investment securities  Taxable 160,043 2,913 1.82% 126,512 2,744 2.17% 99,188 2,645 2.67% Tax-exempt (1) 75,334 3,572 4.74% 66,854 3,576 5.35% 67,554 3,639 5.39% Loans receivable, net (2) 315,213 16,911 5.37% 313,918 17,607 5.61% 339,698 19,380 5.71% 562,517 23,423 4.16% 510,579 23,931 4.69% 511,726 25,672 5.02% 69,163 67,461 65,877 Total 631,680 $ 578,040 $ 577,603 $ Money market and NOW accounts 203,741 $ 313 $ 0.15% 171,295 $ 371 $ 0.22% 162,437 $ 471 $ 0.29% Savings accounts 44,289 29 0.07% 36,004 48 0.13% 31,754 66 0.21% Certificates of deposit 178,508 1,807 1.01% 178,364 2,341 1.31% 187,236 3,249 1.74% Total deposits 426,538 2,149 0.50% 385,663 2,760 0.72% 381,427 3,786 0.99% FHLB advances and other borrowings 59,287 1,761 2.97% 68,929 1,899 2.76% 77,645 2,519 3.24% 485,825 3,910 0.80% 454,592 4,659 1.02% 459,072 6,305 1.37% 84,303 67,238 63,797 61,552 56,210 54,734 Total 631,680 $ 578,040 $ 577,603 $ 3.36% 3.67% 3.65% 19,513 $ 3.47% 19,272 $ 3.77% 19,367 $ 3.78% 1,371 1,345 1,321 18,142 $ 17,927 $ 18,046 $ 115.8% 112.3% 111.5% Year ended December 31, 2011 Year ended December 31, 2010 Year ended December 31, 2012 Total interest-bearing liabilities Liabilities and Stockholders' Equity Interest-bearing liabilities: Assets Interest-earning assets: Total interest-earning assets Non-interest-earning assets Non-interest-bearing liabilities Stockholders' equity Interest rate spread (3) Net interest margin (4) Tax equivalent interest - imputed (1) (2) Net interest income Ratio of average interest-earning assets to average interest-bearing liabilities 26  (1) Income on tax-exempt investment securities is presented on a fully taxable equivalent basis, using a 34% federal tax rate.  (2) Income on tax-exempt loans is presented on a fully taxable equivalent basis, using a 34% federal tax rate.  (3) Interest rate spread represents the difference between the average yield on interest-earning assets and the average cost of interest- bearing liabilities.  (4) Net interest margin represents net interest income divided by average interest-earning assets. 