Well, it does say 3% yearly.

I hope that doesn't mean the min stake age is 365 days.
I'll have a peek at the source.

Edit: The min stake age looks to be 8 hours. The max is unlimited.  Someone holding more than 8 hours should have staked something by now.  Looking through block explorer now...

Edit: I don't see anything that looks like a stake transaction in the last 100 blocks.