condition mean min max ZT0-3 13.95 13.95 13.95 ZT4-7 1.1 1.1 1.1 ZT8-11 7.6499999999999995 7.6499999999999995 7.6499999999999995 ZT12-15 9.200000000000001 9.200000000000001 9.200000000000001 ZT16-19 18.400000000000002 18.400000000000002 18.400000000000002 ZT20-23 16.4 16.4 16.4