condition mean min max ZT0-3 17.1 17.1 17.1 ZT4-7 0.8 0.8 0.8 ZT8-11 21.200000000000003 21.200000000000003 21.200000000000003 ZT12-15 24.2 24.2 24.2 ZT16-19 23.0 23.0 23.0 ZT20-23 16.15 16.15 16.15