condition mean min max ZT0-3 38.45 38.45 38.45 ZT4-7 48.1 48.1 48.1 ZT8-11 31.5 31.5 31.5 ZT12-15 36.150000000000006 36.150000000000006 36.150000000000006 ZT16-19 31.4 31.4 31.4 ZT20-23 18.9 18.9 18.9