condition mean min max ZT0-3 80.160933 80.160933 80.160933 ZT4-7 80.8310005 80.8310005 80.8310005 ZT8-11 79.1969905 79.1969905 79.1969905 ZT12-15 81.4656475 81.4656475 81.4656475 ZT16-19 76.7408085 76.7408085 76.7408085 ZT20-23 90.328986 90.328986 90.328986