condition mean min max ZT0-3 6.05 6.05 6.05 ZT4-7 9.2 9.2 9.2 ZT8-11 9.3 9.3 9.3 ZT12-15 6.35 6.35 6.35 ZT16-19 20.950000000000003 20.950000000000003 20.950000000000003 ZT20-23 3.3 3.3 3.3