condition mean min max ZT0-3 14.426114 14.426114 14.426114 ZT4-7 16.500674 16.500674 16.500674 ZT8-11 15.7166675 15.7166675 15.7166675 ZT12-15 13.349087 13.349087 13.349087 ZT16-19 14.2900275 14.2900275 14.2900275 ZT20-23 17.354868 17.354868 17.354868