condition mean min max ZT0-3 17.4 17.4 17.4 ZT4-7 21.5 21.5 21.5 ZT8-11 12.75 12.75 12.75 ZT12-15 11.149999999999999 11.149999999999999 11.149999999999999 ZT16-19 14.35 14.35 14.35 ZT20-23 36.1 36.1 36.1