condition mean min max ZT0-3 5.6534675 3.625425 7.68151 ZT4-7 6.0321549999999995 6.0321549999999995 6.0321549999999995 ZT8-11 1.813165 1.813165 1.813165 ZT12-15 0 0 0 ZT16-19 4.461065 4.461065 4.461065 ZT20-23 9.859005 9.859005 9.859005