How to make time go faster over a given time

So right now in the image i make the scale of the actor set grow larger at .1, however i want it to make so that when it reaches a given number of seconds the scale of the actor will grow more faster and then loop, grow faster more, loop grow even more faster again and keep on going. i need help and i can’t figure this out. much help appreciated!

I might be missing something here but couldn’t you simply increment by a variable that increases over time.

For example:

I never thought of that! Thanks!