% Net interest margin 2.33% 2.34% 2.31% (0.01)% 0.02% 2.34% 2.33% 0.01% Net fees and service income to operating income ratio 21.3% 24.1% 22.7% (2.8)% (1.4)% 22.7% 23.7% (1.0)% Expense to operating income
% (0.39)% (0.23)% 2.31% 2.42% (0.11)% Net fees and service income to operating income ratio 17.4% 24.1% 21.2% (6.7)% (3.8)% 20.4% 22.5% (2.1)% Cost to income ratio 46.5% 43.1% 45.3% 3.4% 1.2% 45.0% 44.0
% Interest income 18,036,208 16,294,353 1,741,855 10.7 Interest expenses 5,719,962 5,032,721 687,241 13.7 Interest income, net 12,316,246 11,261,632 1,054,614 9.4 Fees and services income 5,201,699 5,022,025
) 2017 2016 Amount % Interest income 3,677,566 3,668,333 9,233 0.3 Interest expenses 1,029,550 1,133,429 (103,879) (9.2) Interest income, net 2,648,016 2,534,904 113,112 4.5 Fees and services income
) (3.6) Interest income, net 2,776,779 2,959,282 (182,503) (6.2) Fees and services income 1,126,870 1,009,220 117,650 11.7 Fees and services expenses 99,298 120,977 (21,679) (17.9) Fees and services income
380,501 10.0 Interest expenses 1,289,834 1,043,324 246,510 23.6 Interest income, net 2,910,770 2,776,779 133,991 4.8 Fees and services income 1,165,317 1,126,870 38,447 3.4 Fees and services expenses
Interest income, net 3,226,986 2,910,770 316,216 10.9 Fees and services income 1,386,307 1,165,317 220,990 19.0 Fees and services expenses 178,540 105,999 72,541 68.4 Fees and services income, net 1,207,767