condition mean min max ZT0-3 112.655681 112.655681 112.655681 ZT4-7 172.860559 172.860559 172.860559 ZT8-11 193.02745149999998 193.02745149999998 193.02745149999998 ZT12-15 157.5672905 157.5672905 157.5672905 ZT16-19 119.688008 119.688008 119.688008 ZT20-23 115.53380200000001 115.53380200000001 115.53380200000001