Android :: Make ScaleAnimation Move Evenly Or Figure Out How It Moves

I used a ScaleAnimation to make a timebar shrink in a game. When the current level was finished, I wanted the timebar to quickly shrink to the bottom. So what I did was that if 30% of the time had passed, I assumed that 30% of the timebar was gone. So I just started a new ScaleAnimation that started at 70% of the timebars original size, assuming that this would look like a single smooth animation that speed up when the level was finished. Unfortunately the scaleanimation does not move evenly. It moves slower at the start and end, and faster in the middle.

So now I have three choices: Either I figure out how to make the ScaleAnimation move in an even speed, or I figure out the formula of how fast it moves, so I can determine exactly how big it is when a certain percent of the animation has played. Or, I find a smarter way altogether to do this timebar.