condition mean min max ZT0-3 11.592943 11.592943 11.592943 ZT4-7 10.8013885 10.8013885 10.8013885 ZT8-11 12.911907 12.911907 12.911907 ZT12-15 12.5864325 12.5864325 12.5864325 ZT16-19 12.512966500000001 12.512966500000001 12.512966500000001 ZT20-23 9.576043 9.576043 9.576043