condition mean min max ZT0-3 10.950000000000001 10.950000000000001 10.950000000000001 ZT4-7 3.8 3.8 3.8 ZT8-11 5.4 5.4 5.4 ZT12-15 6.1000000000000005 6.1000000000000005 6.1000000000000005 ZT16-19 1.75 1.75 1.75 ZT20-23 8.8 8.8 8.8