condition mean min max ZT0-3 22.585439 22.585439 22.585439 ZT4-7 17.2362405 17.2362405 17.2362405 ZT8-11 14.7587485 14.7587485 14.7587485 ZT12-15 16.715654 16.715654 16.715654 ZT16-19 13.9177775 13.9177775 13.9177775 ZT20-23 15.378529499999999 15.378529499999999 15.378529499999999