condition mean min max ZT0-3 17.3625 15.48965 19.23535 ZT4-7 15.913 15.913 15.913 ZT8-11 14.36555 14.36555 14.36555 ZT12-15 0 0 0 ZT16-19 22.1172 22.1172 22.1172 ZT20-23 25.02385 25.02385 25.02385