That depends on initial manufacturing tolerances and how it's used. The better you keep it clean and well-lubricated, the longer it will last. Some people get 1

That depends on initial manufacturing tolerances and how it's used. The better you keep it clean and well-lubricated, the longer it will last. Some people get 15,000km out of their chains, I'm hoping for 5000km or more. I ride about the same distance as you and according to my chain checker the chain is still good enough after 4.5 months ("0.25% wear", change at 0.5%-0.75%).