Purchases of previously owned homes unexpectedly fell in Apr, a sign the industry’s recovery remains uneven.  Contract closings dropped 3.3% to a 5.04M annualized rate after a 5.2M pace that was the strongest in almost 2 years, according to the National Association of Realtors.  The forecast called for a rise to 5.23M.  Prices jumped as the number of houses for sales declined from the same time last year.  Rising prices & a limited supply of properties, combined with too-small growth in pay & lingering concerns about taking on too much debt, are holding the market back.  Signs that younger Americans are forming families & venturing out on their own remain a bright spot that could propel a rebound in the housing industry down the road.  Compared with a year earlier, purchases increased 5.5% before adjusting for seasonal variations.  Existing home sales, tabulated when a purchase contract closes, account for more than 90% of the residential market.  New-home purchases, which make up about 8% & are tabulated when contracts are signed, are considered a timelier barometer.