condition mean min max ZT0-3 15.749049 15.749049 15.749049 ZT4-7 16.4771225 16.4771225 16.4771225 ZT8-11 17.5244995 17.5244995 17.5244995 ZT12-15 14.3427655 14.3427655 14.3427655 ZT16-19 16.1683175 16.1683175 16.1683175 ZT20-23 15.332883500000001 15.332883500000001 15.332883500000001