Compression Test Values

Did a compression test on my 3.5 V8 as its drinking water and oil. 136k miles. Test was done with engine warm, all plugs out. I done each test 3 times and took the average. Results:
Cylinder Dry Wet
1 140 139
2 138 152
3 140 150
4 145 153
5 138 145
6 150 162
7 150 153
8 142 153

What should the compression be for this engine? Looking at these I don't see any reason for head gasket blown - can a fault not show up on a compression test?
I was assuming I was going to have to do an engine rebuild this summer but now not sure it's needed?

Googleage

"originally, the compression was 165 psi" apparently,

Thanks Tim. Any ideas about losing water?

hairline crack in gasket, pressure cap, rad plug, pump gasket, anything water can escape from really

I took the car down my MOT station today and got them to put their emissions probe in the expansion tank to look for exhaust gases. There was no reading at all. So I think I have a coolant leak rather than head gasket issue.