Vermont’s residential real estate market continues its steady climb out of the post-recession doldrums this year, as more first-time buyers have come into the market. Many homes that have awaited buyers for years are finally selling. Experts also said low interest rates, lower gas prices and more optimism about the overall economy have all encouraged a number of younger families and couples to buy first homes in the Green Mountains. In May, closed sales of Vermont homes were up 3.5 percent over May 2015, while the median sales price had dropped by 4.3 percent, according to data from Vermont Realtors. The group also reported that closed sales of single-family homes went up 9.2 percent in May, compared to the same month in 2015.