It can also depend on your usage. If you let the battery drain down below about 45% before charging it, it will start to lose life after anywhere from a month to a year or two, depending on how low you let it go. (50% is the ideal charge point for longevity. 45% is the "I'd better look for an outlet" point. 40% is the "I can't charge it, so I'm turning it off" point. Lower than that is the "I'm shortening the life of the battery" point.)
A year? You can totally ruin a battery in a year (where "totally" means it won't take a charge). Or you can stay between 50% and 100% (as soon as it reaches 100% disconnect the charger, or charge to 99% - which is what you're at the moment the indication is "100%"). Then ... I had to replace my Note 3 battery after a little over 4 years because it started swelling, and if it popped, the stuff that came out would damage the phone. It still works 2 years later, I just won't leave it in the phone. But I consider that a manufacturing defect - there was nothing I could have done to prevent that. My other Note 3 battery [I got one, my wife got one] is still going after just over 6 years. About 97% of capacity. Shut off every single time at 50%, for 6 years. They don't last forever, but long enough that ... who wants the phone? I still have a Samsung Precedent, with 2 good batteries. It's totally useless these days, it uses 2G for voice, which Sprint no longer supports. But the batteries? About 8 years old and still going strong. (I keep them charged - about 2 or 3 times a year. The phone can still be used to watch videos, it can be used on WiFi, etc.)