RE: Changing bow string (how often)
The "safe" answer would be to change it. BUT, there are quite a few variables that need consideration. What type of string is it? How was it taken care of? Waxed? How often? How has it been stored? How much do you shoot it? Are there and broken strands.....
When in doubt, change it.....Or take it to your pro shop and have them look at it.