How long do you typically go before changing your wiper blades?

Change your wiper at least once a year, depending on where you live. If you are of the crummy moronic type, like, leaving them on when it has stopped raining, or wiping too fast, when there is sparce water on windshield. Those with rear wipers, less often, unless you are also visually impaired, and keep them on with scant rain falling down.

If you keep your vehicle garaged, maybe less often, weather extremes are tough on soft rubber.

rubber's life span is greatly influenced by it's exposure to uv, or sunlight. vehicles that are normally garaged and /or parked under cover enjoy longer wiper blade and tire life.

If you can find them, PIAA Silicone blades last a long time, provide a really clean wipe, and lay down a layer of silicone that helps bead up water, which adds to visibility between wipes. I used Bosch Microedge for years, but the PIAA Silicones have uppped the bar. For a car that sits outdoors, you should still see 2 solid years of use from a set.