condition mean min max ZT0-3 3.41912 2.546175 4.292065 ZT4-7 5.215865 5.215865 5.215865 ZT8-11 4.126955 4.126955 4.126955 ZT12-15 0 0 0 ZT16-19 6.318075 6.318075 6.318075 ZT20-23 5.872395 5.872395 5.872395