condition mean min max ZT0-3 13.720212 13.720212 13.720212 ZT4-7 14.522897 14.522897 14.522897 ZT8-11 12.1140695 12.1140695 12.1140695 ZT12-15 13.9925915 13.9925915 13.9925915 ZT16-19 13.7623555 13.7623555 13.7623555 ZT20-23 13.719209 13.719209 13.719209