I am an FO on the 777 and have looked at my last few rosters. Have to say that we get it pretty easy compared compared to the captains:
Mar 7 leave 10 off 4 rest
Apr 5 leave 9 off 6 rest
May 3 leave 11 off 6 rest
average about 67 hrs a month
Reckon it might change towards the end of the year due to the amount of new aircraft arriving !!