A more accurate measure though is staff per passenger per kilometer traveled! This implicitly weights it for long haul versus short haul travel.
evanb is partly right. I saw this stats somewhere a while back and if memory serves me correct, SAA was roughly about 130 staff per airframe. However, this is not a measure of how well an airline is doing. If your fleet is burning fuel on routes with empty seats, your staff per airframe ratio doesnt change. Staff per passenger per kilometer traveled doesn't always necessarily weight it for long haul versus short haul though, unless you are only taking into consideration staff that is directly involved with flights ie cabin crew, handlers, maintenance etc. This whole thing gets complicated but your best bet is to take a look at the financial reports which are usually available on the airline's websites. You'll get a better understanding.