From my experiences, if you rent from an individual the rent usually stays the same as long as you pay on time. However, if you rent from a company (and most apartments are owned by real estate management companies now) they increase the price on every 1 year lease renewal. If you don't like it, there are a dozen more people who want to move in.
Sucks, but that's the way it works. Back when I rented I always hunted for private owners renting out houses and stayed away from apartments as much as I could.
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