condition mean min max ZT0-3 36.8 36.8 36.8 ZT4-7 4.7 4.7 4.7 ZT8-11 13.950000000000001 13.950000000000001 13.950000000000001 ZT12-15 24.200000000000003 24.200000000000003 24.200000000000003 ZT16-19 23.1 23.1 23.1 ZT20-23 27.45 27.45 27.45