Your computer is above the minimum specs in only one area: RAM. Everything else ranges from just slightly below to far below minimum; your CPU is 0.2GHz and 2MB cache short of minimum, and you're running on an Intel integrated graphics chip. To be honest, I'm amazed you've ever gotten even 60 FPS on medium settings in CS:GO.
Given all that, the best way to increase your FPS is either to lower your settings or buy/build a new computer...