condition mean min max ZT0-3 9.25 9.25 9.25 ZT4-7 5.2 5.2 5.2 ZT8-11 18.65 18.65 18.65 ZT12-15 5.550000000000001 5.550000000000001 5.550000000000001 ZT16-19 19.400000000000002 19.400000000000002 19.400000000000002 ZT20-23 14.850000000000001 14.850000000000001 14.850000000000001