condition mean min max ZT0-3 5.813305 5.627545 5.999065 ZT4-7 4.96203 4.96203 4.96203 ZT8-11 5.4888 5.4888 5.4888 ZT12-15 0 0 0 ZT16-19 6.878065 6.878065 6.878065 ZT20-23 8.04796 8.04796 8.04796