(1)  “Fully Indexed” refers to loans where payment adjustments are equal to mortgage interest-rate adjustments. (2)  Loans with potential negative amortization will have increased principal balances, only if interest rates increase, as  compared to loans with scheduled negative amortization, for which an increase in loan balance will occur even if interest  rates do not change. Net Premiums Written and Earned. Net premiums written increased in 2012 compared to 2011, primarily resulting from  a significant increase in NIW in 2012 compared to 2011, as well as an increase in the volume of single premium policies  originated in 2012, which were partially offset by an increase in ceded premiums written, primarily as a result of the  Reinsurance Transactions. See “ Reinsurance ” below. While the volume of single premium policies written in 2012 increased,  the percentage of our total new insurance written as single premium policies decreased to approximately 35% compared to 41%  for 2011 and 20% for 2010. Net premiums written increased in 2011 compared to 2010, primarily due to a decrease in ceded  premiums resulting from the run-of f and termination of captive reinsurance arrangements and an increase in premiums written  on single premium policies. December 31, ($ in millions) 2012 2011 2010 Percentage of primary RIF Refinances. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32% 32% 31% Loan Type: Fixed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91.6% 88.7% 86.8% ARM (fully indexed) (1) Less than five years. . . . . . . . . . . . . . . . 2.1 2.9 3.5 Five years and longer. . . . . . . . . . . . . . . 4.7 6.2 7.0 ARM (potential negative amortization) (2) Less than five years. . . . . . . . . . . . . . . . 1.4 1.9 2.3 Five years and longer. . . . . . . . . . . . . . . 0.2 0.3 0.4 Total . . . . . . . . . . . . . . . . . . . . . . . . . . 100.0% 100.0% 100.0% Total primary RIF by LTV 85.00% and below . . . . . . . . . . . . . . . . . . . . . . . $ 3,292 9.6% $ 2,772 9.0% $ 2,816 8.9% 85.01% to 90.00%. . . . . . . . . . . . . . . . . . . . . . . . 13,134 38.2 11,861 38.7 12,102 38.5 90.01% to 95.00% . . . . . . . . . . . . . . . . . . . . . . . . 13,303 38.7 10,735 35.0 10,506 33.4 95.01% and above . . . . . . . . . . . . . . . . . . . . . . . . 4,643 13.5 5,324 17.3 6,037 19.2 Total Primary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . $ 34,372 100.0% $ 30,692 100.0% $ 31,461 100.0% Total primary RIF by policy year 2005 and prior. . . . . . . . . . . . . . . . . . . . . . . . . . . $ 5,657 16.5% $ 6,887 22.4% $ 8,145 25.9% 2006 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2,735 8.0 3,172 10.3 3,690 11.7 2007 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6,059 17.6 6,960 22.7 8,072 25.7 2008 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4,582 13.3 5,206 17.0 5,935 18.9 2009 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2,021 5.9 2,656 8.7 3,099 9.8 2010 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1,726 5.0 2,244 7.3 2,520 8.0 2011 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2,956 8.6 3,567 11.6 — — 2012 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8,636 25.1 — — — — Total Primary. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . $ 34,372 100.0% $ 30,692 100.0% $ 31,461 100.0% 101