Depends on Category and base. There can be huge differences across the system. I know a 350 reserve F/O who has flown 1 trip in 3 months and had 4 short calls. Our reserve system makes it very difficult to cover longer international trips. Bottom line is be in position for your long and short call obligations. Looking back at the last year is also not going to give you really valid info. They have pulled down block hours and are rapidly catching up training. Reroutes are way down and the predicted 4th of July debacle never happened. Excellent review on staffing in this months crew resources letter.