condition mean min max ZT0-3 10.350000000000001 10.350000000000001 10.350000000000001 ZT4-7 25.6 25.6 25.6 ZT8-11 9.4 9.4 9.4 ZT12-15 16.25 16.25 16.25 ZT16-19 8.5 8.5 8.5 ZT20-23 3.6500000000000004 3.6500000000000004 3.6500000000000004