condition mean min max ZT0-3 13.291517 13.291517 13.291517 ZT4-7 14.811038 14.811038 14.811038 ZT8-11 13.0822495 13.0822495 13.0822495 ZT12-15 12.741863500000001 12.741863500000001 12.741863500000001 ZT16-19 16.906807 16.906807 16.906807 ZT20-23 15.699398500000001 15.699398500000001 15.699398500000001