Is damage to mini blinds considered normal wear and tear?

[Kent Hegwood]

My tenants just moved out and every set of mini blinds were broken and need to be replaced.  The tenants were decent and rented from us for 6 years and other than the blinds, the rest of the house is in good shape. I know blinds are cheap but there are a lot of them that need to be replaced.   Also, I've always had blinds in my personal residence and have never managed to break them.   Would you give them a pass on the blinds? Is this considered normal wear and tear?