condition mean min max ZT0-3 148.138955 148.138955 148.138955 ZT4-7 183.420312 183.420312 183.420312 ZT8-11 223.372139 223.372139 223.372139 ZT12-15 175.2968105 175.2968105 175.2968105 ZT16-19 173.018354 173.018354 173.018354 ZT20-23 171.6966795 171.6966795 171.6966795