condition mean min max ZT0-3 12.891613645 11.852205979999999 13.931021310000002 ZT4-7 12.069439038833334 11.757148897666667 12.381729179999999 ZT8-11 14.110120886666667 13.005757043333332 15.21448473 ZT12-15 14.407819576666666 13.255860963333333 15.55977819 ZT16-19 18.74140781166667 17.840315063333335 19.642500560000002 ZT20-23 17.81984331 16.28582097 19.35386565