raise rental is ok

but not the way you do it,

what you should do is to reflect your desired collection amount and then spread it out in a contract, for example a 3 years contract, you want to collect

$12,420.00
$12,854.70
$13,304.61

on 4th to 6th year. total is $38,579.31

so you want to collect $12,859.77 a year or $1,072 a month instead of the normal $1,000

hope this helps