Weymouth Township is over the hill. No, not literally. The small Atlantic County town is actually just over the Great Egg Harbor River in a rather flat part of the Pinelands National Reserve. But as far is it’s 2,640 residents go, Weymouth holds the top spot on the list of New Jersey towns with the oldest median population at 64.8 years old, the most recent Census data shows. That’s well above the statewide median age of 40.4, and a whopping 46 years older than the state’s town with the youngest median age. The rankings are based on new American Community Survey data released by the U.S. Censu…