condition mean min max ZT0-3 9.608126666666667 7.7181 11.099260000000001 ZT4-7 8.392050000000001 8.392050000000001 8.392050000000001 ZT8-11 7.679875 7.679875 7.679875 ZT12-15 11.786999999999999 10.77435 12.79965 ZT16-19 10.602084999999999 10.602084999999999 10.602084999999999 ZT20-23 12.0861 12.0861 12.0861