condition mean min max ZT0-3 7.622655 7.4273299999999995 7.81798 ZT4-7 3.92856 3.92856 3.92856 ZT8-11 5.60901 5.60901 5.60901 ZT12-15 0 0 0 ZT16-19 8.289 8.289 8.289 ZT20-23 6.132664999999999 6.132664999999999 6.132664999999999