Is 150 PSI compression enough on a 2009 Kawa Ninja 250R?

Couldn't find a lot of info online. Basically I was suspecting coolant getting into the engine, so I did a compression test and got 150 PSI. It's got a ratio of 11.6 : 1 so it should be more towards 170 PSI right? I'm not sure if it's a big enough difference to be of concern. Both cylinders were nearly exactly 148-150 max.

I should mention it took like 7-8 turns to get 150 PSI and at 4 turns it was more around 90 PSI.