condition mean min max ZT0-3 173.634692 173.634692 173.634692 ZT4-7 196.5052715 196.5052715 196.5052715 ZT8-11 281.065514 281.065514 281.065514 ZT12-15 149.05262349999998 149.05262349999998 149.05262349999998 ZT16-19 78.844469 78.844469 78.844469 ZT20-23 34.2608475 34.2608475 34.2608475