condition mean min max ZT0-3 3.553320497 3.4980105239999997 3.6086304700000005 ZT4-7 3.1637242532500003 3.0625887545 3.2648597520000004 ZT8-11 3.755707898 3.151564574 4.359851222 ZT12-15 6.56816722575 5.788055902 7.3482785495 ZT16-19 7.209624913000001 6.9893101820000005 7.429939644 ZT20-23 8.33240611475 8.2331983865 8.431613843