Here's a sweet piece of info, too...
When we calibrate our hygrometers at 75%, that's the point where they're accurate (calibrated).
At 65% they can be 3 or 4 points off, and are usually at least 2 points off. (I say that from experience. I use somewhere around 20 hygrometers for making beads and I calibrate them all at least once a month.)
It really doesn't matter, either.
The hygrometer is just a guide. If my cigars are smoking well at what my hygrometer says is 65% but is actually 63%, it really means nothing.
If my hygrometer says 69% and it's really 60%, same thing.
The only time the inaccuracy comes into play is if I switch hygrometers. If I put a new one in and it reads 61% where the old one read 69%, I'm sure not going to start trying to get my RH%age up.
Another thing about hygrometers is that once the battery gets low, they are notoriously wonky. The very first thing I do when a hygro in one of my humis is off?
I get a different hygrometer and put it in there.
Then I change the battery in the screwy one.
99% of the time it's the hygro that's screwed up and not my humi.
All that was to say this...
Trust your cigars first and your hygrometer second.
After a period of time, you're honestly going to be able to pick up a cigar and know immediately if it's too dry or too wet.