condition mean min max ZT0-3 3.0610425 2.72093 3.401155 ZT4-7 2.99619 2.99619 2.99619 ZT8-11 4.1616599999999995 4.1616599999999995 4.1616599999999995 ZT12-15 0 0 0 ZT16-19 12.845849999999999 12.845849999999999 12.845849999999999 ZT20-23 8.03886 8.03886 8.03886