condition mean min max ZT0-3 48.239448 48.239448 48.239448 ZT4-7 23.206857 23.206857 23.206857 ZT8-11 23.113148000000002 23.113148000000002 23.113148000000002 ZT12-15 28.507558 28.507558 28.507558 ZT16-19 13.686490500000001 13.686490500000001 13.686490500000001 ZT20-23 27.663207 27.663207 27.663207