PFR vs UO PFR

[SkyWalker01]

Which is the difference between this 2 stats? I ask you because when i see the reports in the hm i see a big gap in %
ie:
Pfr button 16%
uo pfr button 37%

tks

[Patvs]

PFR = preflop raise.
If a person limps in front of you... and you raise. This will affect your PFR%


UO PFR = unopened preflop raise.
Unopened means you're the first player to act. (so one one has limped/raised in front of you)