condition mean min max ZT0-3 17.87115 17.5138 18.4543 ZT4-7 23.91115 23.91115 23.91115 ZT8-11 13.45655 13.45655 13.45655 ZT12-15 15.661650000000002 14.6882 16.6351 ZT16-19 15.356449999999999 15.356449999999999 15.356449999999999 ZT20-23 18.69745 18.69745 18.69745