The average for me would be somewhere in the low 60s.. I think the youngest was 59, highest was 68. It can depend on whether you're using organics in the fridge, giving them vitamins, fruits and hand gels to work on their health and praising them when they do good things for their health like work out.
Even with all the pampering we give them, it seems to be random when they die and there's not much we can do.

Good luck with the parents!