condition mean min max ZT0-3 14.195344 14.195344 14.195344 ZT4-7 12.017565000000001 12.017565000000001 12.017565000000001 ZT8-11 11.3467855 11.3467855 11.3467855 ZT12-15 12.5945735 12.5945735 12.5945735 ZT16-19 14.431934 14.431934 14.431934 ZT20-23 13.2949 13.2949 13.2949