That 89 average is very good. My rides tend to average 75 to 80 rpm, even when I'm spinning in the 90s a lot during the ride. Easier paced portions usually have a lower cadence, down to the 70s. And hills are mostly low cadence, although I do like to climb at 90 rpm if the gearing allows it.
I have Di2 electric shifting, so it's easy for me to shift a lot. I'm always searching for the best feeling cadence. I'll sometimes shift for just a couple of revolutions, then shift again.