condition mean min max ZT0-3 7.2657975 6.37676 8.154835 ZT4-7 6.558339999999999 6.558339999999999 6.558339999999999 ZT8-11 5.43103 5.43103 5.43103 ZT12-15 0 0 0 ZT16-19 6.111235 6.111235 6.111235 ZT20-23 6.61968 6.61968 6.61968