U.S. households increased their debt last quarter by 0.3 percent as mortgage balances showed a “small increase,” the Federal Reserve Bank of New York said today. Consumer indebtedness totaled $11.5 trillion at the end of March, up $33 billion from Dec. 31, 2010, according to the New York Fed’s quarterly report on household debt and credit. Households have slashed $1.03 trillion, or 8.2 percent, from outstanding consumer debts since the peak in the third quarter of 2008, the New York Fed said. Delinquency rates declined for the fifth straight quarter, with 10.5 percent of outstanding debt being in “some stage of delinquency,” down from 10.8 percent on Dec. 31, according to the New York Fed. That’s also down from 11.9 percent a year earlier, the survey said. Credit-card limits rose by about $30 billion, or 1 percent, in the first increase since the third quarter of 2008, and credit card balances declined by 4.6 percent, according to the survey.