condition mean min max ZT0-3 18.718233333333334 11.26195 22.45485 ZT4-7 8.801765 8.801765 8.801765 ZT8-11 11.74735 11.74735 11.74735 ZT12-15 11.738025 10.6472 12.82885 ZT16-19 15.437549999999998 15.437549999999998 15.437549999999998 ZT20-23 23.481099999999998 23.481099999999998 23.481099999999998