It's made up of a few different things - less state/federal government support, drying up economy (less companies paying taxes), and things cost more. We also live in a sprawl area, so more schools being built, etc. I've lived here for 10 years and for 10 years the property taxes have gone up. I would consider moving, but my kids are in middle/high school and I am trying my best to not uproot if I can avoid it.
Didn't really answer the questions. Do your property taxes increase because the rates increased or because the assessed value of your property increased, or perhaps because your governments added flat per-parcel fees?
I re-assessed many years (5+) ago to get it as low as possible and haven't had that changed. The selling price of the homes went down with everyone else in 2k7, and have slowly gotten better to maybe worth a little more than what we paid for. It's really do to what I listed.
I thought I stated, but I guess not clearly, that it is due to the mill rate increasing every year for the past 10 years due to the factors I listed, not valuation.