condition mean min max ZT0-3 13.25 13.25 13.25 ZT4-7 12.9 12.9 12.9 ZT8-11 31.200000000000003 31.200000000000003 31.200000000000003 ZT12-15 34.05 34.05 34.05 ZT16-19 23.45 23.45 23.45 ZT20-23 11.9 11.9 11.9