What is the maximum Ambition and Professionalism values can I enter in my staff's personality attributes column ?

When i enter 127 some of my staffs retire early even when they are in their mid-30's . If I change those values for staffs over the age of 45 will they still reach their potential ?

I just want my staff's attributes to improve gradually over time rather than setting them high and freezing it .

Thanks for those who reply.

I have sent them to 30 each and left it at that.  Maybe they retire early as they want to achieve more rather than staying at their current level hence the high Ambition stat.