condition mean min max ZT0-3 11.458725 10.495899999999999 12.42155 ZT4-7 7.67798 7.67798 7.67798 ZT8-11 8.777935 8.777935 8.777935 ZT12-15 0 0 0 ZT16-19 12.4055 12.4055 12.4055 ZT20-23 12.466249999999999 12.466249999999999 12.466249999999999