How often do you upgrade your phone?

I know some people who always rush to get the new iPhone as soon as it drops every year. But there aren't such big changes or improvements to justify upgrading every year. It's only worth it, in my opinion, every 4 to 5 years. This way, you'll feel happier about your new device, and you'll have saved a good amount of money.

So, tell us about your upgrade pattern. How often do you get a new phone?