condition mean min max ZT0-3 2.1445375 1.99972 2.289355 ZT4-7 2.123855 2.123855 2.123855 ZT8-11 2.5789999999999997 2.5789999999999997 2.5789999999999997 ZT12-15 0 0 0 ZT16-19 2.9065849999999998 2.9065849999999998 2.9065849999999998 ZT20-23 2.655005 2.655005 2.655005