condition mean min max ZT0-3 10.665908 10.665908 10.665908 ZT4-7 11.235309 11.235309 11.235309 ZT8-11 11.068076000000001 11.068076000000001 11.068076000000001 ZT12-15 11.0931915 11.0931915 11.0931915 ZT16-19 9.7606425 9.7606425 9.7606425 ZT20-23 11.9273185 11.9273185 11.9273185