condition mean min max ZT0-3 13.595133333333333 7.15975 17.2209 ZT4-7 5.989855 5.989855 5.989855 ZT8-11 4.898035 4.898035 4.898035 ZT12-15 7.03576 6.518705000000001 7.552815 ZT16-19 12.716249999999999 12.716249999999999 12.716249999999999 ZT20-23 18.79475 18.79475 18.79475