condition mean min max ZT0-3 22.55305 22.55305 22.55305 ZT4-7 15.976849999999999 15.976849999999999 15.976849999999999 ZT8-11 18.63345 18.63345 18.63345 ZT12-15 22.194850000000002 22.194850000000002 22.194850000000002 ZT16-19 29.654000000000003 29.654000000000003 29.654000000000003 ZT20-23 28.1311 28.1311 28.1311