Home prices have regained nearly half of the value lost since prices peaked in June 2006 and prices rose 1.5 percent last month and 4.5 percent above January prices. Existing-home sales in the West increased 2.5 percent to a pace of 1.23 million in May and are 7.0 percent above a year ago. With the tightest regional supply, the median price in the West was $276,400, up 19.9 percent from May 2012, according to the National Association of Realtors. Sales have stayed above year-ago levels for 23 months, while the national median price shows 15 consecutive months of year-over-year increases. The same rising prices that are boosting inventories also drove investors out of the market, according to the latest Campbell/Inside Mortgage Finance HousingPulse Tracking Survey. The investor share of home purchases tumbled from 22.0 percent in April to 20.2 percent in May based on a three-month moving average. That was the sharpest drop in investor activity recorded in more than three years. According to NAR, Individual investors purchased 18 percent of homes in May; they were 19 percent in April. Both current homeowners and first-time homebuyers increased their participation in the home purchase market between April and May. Current homeowners accounted for 43.8 percent of home purchases last month while first-time homebuyers represented 36.0 percent in May, HousingPulse results showed.