condition mean min max ZT0-3 26.05 26.05 26.05 ZT4-7 4.4 4.4 4.4 ZT8-11 20.8 20.8 20.8 ZT12-15 18.900000000000002 18.900000000000002 18.900000000000002 ZT16-19 4.05 4.05 4.05 ZT20-23 4.55 4.55 4.55