condition mean min max ZT0-3 3.3670966666666664 2.4441249999999997 4.328555 ZT4-7 5.738424999999999 5.738424999999999 5.738424999999999 ZT8-11 1.7138360000000001 1.7138360000000001 1.7138360000000001 ZT12-15 1.2707220000000001 1.0049975 1.5364465 ZT16-19 3.6487299999999996 3.6487299999999996 3.6487299999999996 ZT20-23 2.20794 2.20794 2.20794