For me, they tried to get $100 monthly increase each year/renewal. Sometimes (though not always) they will come down off of their original renewal offer, though they generally won't negotiate if you're renewing for less than the 12-month renewal term. Post starts you out at a relatively low rate, but soon enough, you find yourself paying $1300/mo for an apartment they'd get $900/mo for from a new resident. They figure you won't want to cough up the $ to move (not to mention go through the hassle of moving) so they've got you right where they want you. This may be true of all apartment complexes, but in my experience, Post is ruthless in this area.

I was in a one bedroom apartment, with rent increases of about $40 per month with each renewal. Started off at about $800 per month, so around a 5% monthly increase? Doesn't seem excessive to me.

I noticed the same. I lived there for two years. 12 month lease each time. My rent went up by around 5% each year which is in line with other apartments i've lived in.