Department of Housing and Urban Development, U.S. Housing Conditions, various issues. All conventional mortgages from 1984 to 1997, then “prime” conventional mortgages from 1998 to 2008 (first quarter). Prior to 1998, mortgages were not distinguished by borrower credit ratings. “90 days” is the percent of mortgage payments that are 90 days late. “Foreclosure” are those actually in foreclosure.