condition mean min max ZT0-3 8.7637 8.7637 8.7637 ZT4-7 8.730380499999999 8.730380499999999 8.730380499999999 ZT8-11 8.5618885 8.5618885 8.5618885 ZT12-15 8.5092575 8.5092575 8.5092575 ZT16-19 9.357777500000001 9.357777500000001 9.357777500000001 ZT20-23 9.314638500000001 9.314638500000001 9.314638500000001