condition mean min max ZT0-3 9.963465 8.19043 11.7365 ZT4-7 2.9324149999999998 2.9324149999999998 2.9324149999999998 ZT8-11 1.254105 1.254105 1.254105 ZT12-15 0 0 0 ZT16-19 3.0641100000000003 3.0641100000000003 3.0641100000000003 ZT20-23 2.733415 2.733415 2.733415