The cost of filling your gas tank continues to mount. The latest Lundberg Survey shows motorists are paying 20 cents more per gallon than they did two weeks ago. The survey indicates the national average price of regular gas was about three-79 a gallon on Friday. Gas prices have gone up more than 53 cents in the past nine weeks. Trilby Lundberg says she thinks she can see a light at the end of the tunnel. She adds the latest increase hides a drop in wholesale prices over the last few days. According to Gasbuddy.Com, the average price for a gallon of regular unleaded in Washington this morning was $3.73. In Vincennes it was $3.87. It was $3.79 in Petersburg.