condition mean min max ZT0-3 31.5 31.5 31.5 ZT4-7 21.6 21.6 21.6 ZT8-11 14.25 14.25 14.25 ZT12-15 24.45 24.45 24.45 ZT16-19 25.200000000000003 25.200000000000003 25.200000000000003 ZT20-23 16.05 16.05 16.05