condition mean min max ZT0-3 20.876759 20.876759 20.876759 ZT4-7 18.87077 18.87077 18.87077 ZT8-11 24.6424855 24.6424855 24.6424855 ZT12-15 24.303103 24.303103 24.303103 ZT16-19 23.825485500000003 23.825485500000003 23.825485500000003 ZT20-23 24.4717905 24.4717905 24.4717905