condition mean min max ZT0-3 11.863855 9.437365 13.22955 ZT4-7 8.826475 8.826475 8.826475 ZT8-11 8.214269999999999 8.214269999999999 8.214269999999999 ZT12-15 13.768225 12.623899999999999 14.91255 ZT16-19 13.241 13.241 13.241 ZT20-23 14.4854 14.4854 14.4854