condition mean min max ZT0-3 16.742901 16.742901 16.742901 ZT4-7 53.0550115 53.0550115 53.0550115 ZT8-11 47.0729105 47.0729105 47.0729105 ZT12-15 40.6708985 40.6708985 40.6708985 ZT16-19 28.0631455 28.0631455 28.0631455 ZT20-23 23.091377 23.091377 23.091377