condition mean min max ZT0-3 23.500572 23.500572 23.500572 ZT4-7 22.368828999999998 22.368828999999998 22.368828999999998 ZT8-11 23.1187495 23.1187495 23.1187495 ZT12-15 28.3848755 28.3848755 28.3848755 ZT16-19 21.710586499999998 21.710586499999998 21.710586499999998 ZT20-23 22.633427 22.633427 22.633427