condition mean min max ZT0-3 24.86885 23.428849999999997 26.30885 ZT4-7 28.818649999999998 28.818649999999998 28.818649999999998 ZT8-11 18.106 18.106 18.106 ZT12-15 0 0 0 ZT16-19 21.575 21.575 21.575 ZT20-23 25.191000000000003 25.191000000000003 25.191000000000003