Confused bb/100

[MrTop]

Okay, I admit it, I'm confused with this whole BB/100 when it comes to NL. I've been focusing on the 6 max 100nl games for a bit now and have logged 30k+ hands multi tabling (usually 3). My win rate throughout this ~11 big blinds per 100 (before bonuses and RB). In no limit, does this equate to 11bb/100 or 5.5bb/100?

Also, is 30k hands really enough of a sample?

I think that I'm doing well, but 5.5 seems like it could be bettered.