condition mean min max ZT0-3 29.6 29.6 29.6 ZT4-7 14.3 14.3 14.3 ZT8-11 6.5 6.5 6.5 ZT12-15 31.849999999999998 31.849999999999998 31.849999999999998 ZT16-19 21.200000000000003 21.200000000000003 21.200000000000003 ZT20-23 11.9 11.9 11.9