Residential sales in Manhattan continued to slide in the second quarter, according to market reports released today, falling back from last year's lofty peaks. Real estate and appraisal company Miller Samuel, in a quarterly report prepared for Prudential Douglas Elliman Real Estate, reported that sales of all co-ops and condos fell 21.8 percent in the second quarter compared to the same quarter last year, with inventory swelling 31.2 percent and the median sale price rising 14.5 percent. In a separate report, real estate data company PropertyShark.com and The Corcoran Group reported a 38 percent year-over-year drop in sales in the second quarter, with the median sale price up 13 percent. "This is like the first-quarter redux," said Jonathan Miller, president and CEO for ...