Difficulty & Network Hash Increase

The difficulty has gone from 80TH to 130TH and the network hash rate has gone from 5700GH to 9700GH since January 1,2017. Anybody have a good explanation of how the the network hash rate has gone up nearly a 100GH a day? Is there a secret out on how to increase your hash rate? I guess no one will post if it is secret I know there are the new pandaminers, but they use just as much electricy as grfx cards...