Math Problem Help/In-game Avatar Aging?

Alright so I have made a simple game where your avatar ages. The avatar starts at the age of 0 and progresses to the age of 70, then it will die of age. It will reach the age of 70 after 100 hours of game play. So my question is,

If the in-game avatar will reach age 70 after 100 play time hours, how many "months" will the avatar age every hour. Round to the closest whole number if you have to.

Thank you

It would be 8.4mo / hr. For future reference: this site is for scripting help, not mathematics help.