condition mean min max ZT0-3 490.802201 490.802201 490.802201 ZT4-7 290.5417535 290.5417535 290.5417535 ZT8-11 275.771259 275.771259 275.771259 ZT12-15 291.77101749999997 291.77101749999997 291.77101749999997 ZT16-19 273.235166 273.235166 273.235166 ZT20-23 289.769334 289.769334 289.769334