Like Patches said, they will vary.
Best thing you can do is be kind to your liver!
NO alcohol if you can (I had to have help on that one); watch your acetaminophen usage; if you take vitamins, consider ones with no iron (often called 'mature multi-vitamins'); watch what you eat (don't want a fatty liver); and get some exercise.
Good luck, Chris
your alt and ast will always vary a little