condition mean min max ZT0-3 20.459452 20.459452 20.459452 ZT4-7 16.845179 16.845179 16.845179 ZT8-11 15.6530825 15.6530825 15.6530825 ZT12-15 14.9265545 14.9265545 14.9265545 ZT16-19 11.8856745 11.8856745 11.8856745 ZT20-23 10.666789999999999 10.666789999999999 10.666789999999999