Hi nicholas welcome to our forum. Hope you find it interesting and dob't hesitate to ask questions here.
Apple snails' life span depends on temperature and general life conditions.In our hot environment don't except them to live more then 2 years. In high temperatures these snails are more active and their metobolism increases, so it shortens their life expectancy. So to elongate their life you have to keep them in cooler places. Some apple snails were even reported to live over 10 years.