condition mean min max ZT0-3 0.3247926666666667 0.1358905 0.4903445 ZT4-7 0.3324195 0.3324195 0.3324195 ZT8-11 0.069779 0.069779 0.069779 ZT12-15 0.03795925 0.0 0.0759185 ZT16-19 0.33580499999999996 0.33580499999999996 0.33580499999999996 ZT20-23 0.446847 0.446847 0.446847