OK giving this a try until I get bored. I'm using the Smogon website for each tier in SM (I don't see USUM anywhere). For example OU here. Each page has a table with the Pokemon and stats so I ran some quick calculations in JavaScript using Chrome Dev Tools on each page.
Format | HP | Atk | Def | SpA | SpD | Spe
Uber | 103.0 | 125.0 | 104.0 | 127.1 | 104.7 | 110.0
OU | 83.4 | 108.6 | 98.7 | 99.9 | 95.8 | 86.8
UU | 85.8 | 95.6 | 92.1 | 91.3 | 89.4 | 86.2
RU | 81.8 | 96.2 | 93.7 | 86.5 | 90.5 | 76.0
NU | 80.1 | 85.2 | 84.8 | 80.1 | 84.5 | 78.0
PU | 77.0 | 85.0 | 81.6 | 76.4 | 80.6 | 71.2
Those are all the main tiers I think.
