Repairs/Maintenance

[Scott Bastarache]

I was wondering what some of you guys use to calculate the annual expence for your repairs and maintenance on a property if there is no info given to you to track the history of the property. Does anyone have a formula they use depending on the type of property ( one/two/three family etc.) I am trying to figure out a system that I can accurately come up with a number to insert into a speculated APOD and feel comfortable the number is going to be relatively close. Any help appreciated.

Thanks