broken door kobs/locks at tenancy end- normal wear and tear?

[Shelley A.]

At the end of tenancy, the new tenants immediately complained about door knobs that were jammed.  The handyman said he tried to repair them but most needed to be replaced. One was  deadbolt and lever handle set on the front door, a bathroom door, and a exterior french door. All of the door knobs and locks worked at the beginning of their tenancy 1.5 years ago.  The old tenants said they never had a problem with the door handles, the handyman confirmed they needed to be replaced. It's a high end home and I go out every year to fix any problems the tenants have.  Since all the door knobs worked at the start of tenancy and some did not work at the end of tenancy, would replacing the door knobs be considered normal wear and tear? Or is it something I can take out of their deposit?  Had the old tenants noticed the problem I would have taken care of the replacement myself after them moved out, but since they didn't notice I had to hire a handyman and the bill came to $265 for working on 5 door knobs. (i don't live nearby)