Purchase and refinance applications dropped precipitously during the week ended Dec. 21, according to data released Thursday by the Mortgage Bankers Association. The Market Composite Index, a measure of overall mortgage loan application volume, fell 7.6 percent on a seasonally-adjusted basis to 603.8; in spite of the weekly drop, application activity remained up 9.9 percent compared with the same week one year earlier. (The index is calibrated to March 16, 1990; a reading of 603.8 means that application activity is roughly 6 times greater than when the index was first established.) Refinance applications fell 8.5 percent to 1915.3, the MBA said, while purchase applications fell 6.6 percent to 394.5 in spite of a drop in interest rates. Refinance share of overall mortgage applicatins activity decreased to 53 percent of total applications from 53.2 percent the previous week. Adjustable-rate mortgage share, however, increased to 10.4 from 9.9 percent of total applications from the previous week. For more information, visit http://www.mortgagebankers.org.