Increase rent to tenants

Why not to increase the rent for the current tenants?

Every renewal period we do an exhaustive analysis of rental prices around the area. If there is an increase in these prices we compare the increment in rent to the monthly rental divided by 12 months (real estate commission divided by 12) and try to make a fair judgement between increasing the rental; hence losing the tenant and spending time looking for another qualified tenant paying real estate commission or simply renewing the tenant at the same price or with a very reasonable increase that would save the lost time, payment of real estate commission and move-out