U.S. residents with mortgages (roughly 63 percent of all homeowners) have seen their equity increase by a total of $766.4 billion in the year since the first quarter of 2016, an increase of 11.2 percent. Additionally, the average American homeowner gained about $13,400 in equity between Q1 2016 and Q1 2017, according to a recent report from CoreLogic, a global property analytics firm.

Of the 10 largest metropolitan areas by population, San Francisco-Redwood City-South San Francisco had the highest percentage of mortgaged properties in a positive equity position at 99.4 percent. Boston was the fifth-highest in the country at 95.6 percent.

In Q1 2017, the total number of mortgaged residential properties with negative equity decreased 3 percent from Q4 2016 to 3.1 million homes, or 6.1 percent of all mortgaged properties. Compared to Q1 2016, negative equity decreased 24 percent in the first quarter of 2017 from 4.1 million homes, or 8.1 percent of all mortgaged properties.

“One million borrowers achieved positive equity over the last year, which means mortgage risk continues to steadily decline as a result of increasing home prices,” Dr. Frank Nothaft, chief economist for CoreLogic, said in a statement accompanying the report’s release.

Negative equity, often referred to as being “underwater” or “upside down,” applies to borrowers who owe more on their mortgages than their homes are worth. Negative equity can occur because of a decline in home value, an increase in mortgage debt or both.

Negative equity peaked at 26 percent of mortgaged residential properties in Q4 2009 based on CoreLogic equity data analysis, which began in Q3 2009.

The national aggregate value of negative equity was approximately $283 billion at the end of Q1 2017, down quarter over quarter by approximately $2.6 billion, or 0.9 percent, from $285.5 billion in Q4 2016 and down year over year by approximately $21.5 billion, or 7.1 percent, from $304.5 billion in Q1 2016.

“Homeowner equity increased by over $750 billion during the last year, the largest increase since mid-2014,” Frank Martell, president and CEO of CoreLogic, said in a statement. “The rising cushion of home equity is one of the main drivers of improved mortgage performance. It also supports consumer balance sheets, spending and the broader economy.”