Here’s an eye-popping statistic: More than 25 percent of the bucks taken in Massachusetts in 2000 were three years old or older, and the spread of mature bucks is statewide. In fact, Bill Woytek, state deer project leader, insists that no single area of the state produces trophy bucks better than another does. But word is that Zone 6 in the Quabbin watershed still has the top trophy potential, having produced one of the state’s two B&C; bucks four years ago. Franklin County is a backup hot spot for big bucks. In addition to the outstanding age composition among its whitetails, Massachusetts also holds a fairly high deer population that was not adversely affected by the harsh winter that struck much of New England. Going into this season, Woytek estimates that the deer herd should be about 90,000 animals and states that numbers are growing by 10 to 15 percent every year in eastern Massachusetts but are stable in much of the western half.