condition mean min max ZT0-3 12.861729 12.861729 12.861729 ZT4-7 11.7368585 11.7368585 11.7368585 ZT8-11 11.820174 11.820174 11.820174 ZT12-15 9.756865 9.756865 9.756865 ZT16-19 11.3303285 11.3303285 11.3303285 ZT20-23 11.406549 11.406549 11.406549