condition mean min max ZT0-3 31.55 31.55 31.55 ZT4-7 15.6 15.6 15.6 ZT8-11 23.05 23.05 23.05 ZT12-15 27.8 27.8 27.8 ZT16-19 26.200000000000003 26.200000000000003 26.200000000000003 ZT20-23 32.5 32.5 32.5