condition mean min max ZT0-3 158.693595 158.693595 158.693595 ZT4-7 137.41774199999998 137.41774199999998 137.41774199999998 ZT8-11 159.733656 159.733656 159.733656 ZT12-15 186.3406755 186.3406755 186.3406755 ZT16-19 218.0956995 218.0956995 218.0956995 ZT20-23 238.61682100000002 238.61682100000002 238.61682100000002