The reason that your variable is being updated every time is that by using the ! notation you have declared it as an instance variable of your jsp page. The instance of this page will stay alive as it were, for the entire time that the server is up, the variable will be incremented by every access of this page (which will include reloads). Due to the fact that every request will access the same instance of the page.
I think I have mixed up some terms here but I hope you get my meaning