condition mean min max ZT0-3 66.0144083 54.02754401 78.00127259 ZT4-7 32.1607619125 28.06909011 36.252433714999995 ZT8-11 28.177949645 26.713513980000002 29.64238531 ZT12-15 16.813101795 16.044236195 17.581967395 ZT16-19 20.52729218 16.70154324 24.35304112 ZT20-23 36.992003832500004 34.909548365 39.0744593