condition mean min max ZT0-3 4.060101666666667 3.080725 5.723995 ZT4-7 4.155765000000001 4.155765000000001 4.155765000000001 ZT8-11 3.175315 3.175315 3.175315 ZT12-15 8.99668 8.754505 9.238855 ZT16-19 5.692970000000001 5.692970000000001 5.692970000000001 ZT20-23 6.350795 6.350795 6.350795