condition mean min max ZT0-3 9.642565000000001 9.642565000000001 9.642565000000001 ZT4-7 2.7630850000000002 2.7630850000000002 2.7630850000000002 ZT8-11 4.59729 4.59729 4.59729 ZT12-15 5.50127 5.50127 5.50127 ZT16-19 6.232905 6.232905 6.232905 ZT20-23 8.029029999999999 8.029029999999999 8.029029999999999