Seniors’ home equity drifted to $4.22 trillion at the end of 2007, down from $4.25 trillion at the end of 2006.

Researchers at the National Reverse Mortgage Lenders Association, Washington, have included those figures in a report on the NRMLA Mortgage Market Index.

The index declined to 201.9 in the last quarter of 2007, from 203.2 a year earlier.