condition mean min max ZT0-3 16.5901249665 8.532693383 24.647556549999997 ZT4-7 20.44701964 19.237800575 21.656238705 ZT8-11 17.00132809 16.037229505 17.965426675 ZT12-15 21.316353195 14.781224375 27.851482015000002 ZT16-19 50.7696728225 45.450238075 56.089107569999996 ZT20-23 48.326843780000004 47.08576969 49.56791787