The demand for homes continues its downward slide. Mortgage applications, a measure of home sales in the pipeline, fell 18.6 percent for the week ending December 17, according to the Mortgage Bankers Association. The sixth straight week of declines in refinance applications, a whopping 24.6 percent, reflecting the continued increase in mortgage interest rates. The flow of new purchase applications slumped 2.5 percent. The decrease in mortgage activity may be in part due to the holiday season, which typically brings a slowdown in real estate activity.