Affordability is a much more pertinent issue for renters than homeowners, according to new research from CoreLogic, a real estate data firm. Since 2005, the monthly cost to rent a single-family home has risen significantly, while the monthly principal-and-interest mortgage payments of homeowners dropped slightly.

CoreLogic’s national rent index jumped 36 percent in December 2018 compared to December 2005. On the other hand, the typical mortgage payment fell 4 percent over that same period.

Researchers say mortgage rates have made a big difference in the change. In December 2005, the 30-year fixed-rate mortgage averaged 6.3 percent. In December 2018, 30-year rates were at a considerably lower average of 4.6 percent. Even though the median sales price in 2005 was only $190,000, compared to $220,305 in 2018, the typical monthly mortgage payment was still lower because of the lower mortgage rates ($941 in 2005 versus $904 in December 2018), researchers note.

CoreLogic factored in about a dozen of the largest metro areas and found seven posted rent increases of 27 to 61 percent between December 2005 and December 2018. That coincided with declines in the typical mortgage payment that ranged from 3 to 24 percent.

Homeowners are less “cost burdened” than renters. In 2017, about 27 percent of homeowners with a mortgage were considered “cost burdened,” which means 30 percent or more of their income was devoted toward the monthly mortgage payment and owner expenses. That has dropped 10 percentage points since 2007, according to U.S. Census Bureau data. On the flip side, 46 percent of renters were considered cost-burdened in 2017, up slightly from 45.6 percent in 2007.

“The share of cost-burdened renters remained fairly steady over that decade while the share of cost-burdened owners dropped significantly,” researchers noted. Homeowners may have been able to lessen their costs by refinancing—sometimes repeatedly—as mortgage rates dropped during that period, researchers say. Also, during the foreclosure crisis in 2007 and 2008, some homeowners may have lost their home due to higher costs. They wouldn’t have been represented in the 2017 data since they are no longer homeowners, researchers add.

In recent months, rental prices have shown signs of cooling, and mortgage payments are starting to inch up due to higher home prices, CoreLogic researchers added.