For most of the last six years I’d say about six hours per week for about 48 weeks each year. There are an average of four weeks (usually called February) when our trails are ice covered and I don’t ride.
This year it’s a bit less per week, as I’m running a couple times a week and/or working out at the rec center, so bike is a smaller fraction of the rotation. Varies from three to nine hours. Average speeds have gone up a bit on the flatter routes to about 18 mph since I switched from single speed and gained the option of a 77 inch gear instead of just 67 inch gear. Hilly, technical routes are limited by other factors.
Otto