condition mean min max ZT0-3 8.05 8.05 8.05 ZT4-7 5.5 5.5 5.5 ZT8-11 14.15 14.15 14.15 ZT12-15 14.75 14.75 14.75 ZT16-19 30.200000000000003 30.200000000000003 30.200000000000003 ZT20-23 20.85 20.85 20.85