Mortgage borrowers in Colorado ended the last decade in a much better place than where they started it, especially along the Front Range. Only 2.8% of Colorado mortgages were “seriously underwater” in the fourth quarter, meaning the loan was 125% or more above the home’s market value, according to an analysis provided by ATTOM Data Solutions. That ranks as the fifth-lowest ratio of seriously underwater homes after Washington, Oregon, California, and Hawaii. Colorado also ranks high, eighth overall, for its share of “equity-rich” mortgages, defined as those with a remaining balance at half or less of a home’s value.