I think the stat would be a lot more meaningful if it only included putts for those that were on Greens in Requlation. If you are off the green on your approach, these guys are all good enough to be able to chip it close enough to have almost 0% 3 putting instances.
Again, that would only be true if there is some significant difference in GIR % between then and now. Most of the stats I see every now and then show very little statistical changes in those areas. Only significant changes I have seen in data are related to driving distances.