condition mean min max ZT0-3 11.81855 11.81855 11.81855 ZT4-7 9.255535 9.255535 9.255535 ZT8-11 8.962985 8.962985 8.962985 ZT12-15 8.51121 8.51121 8.51121 ZT16-19 10.40655 10.40655 10.40655 ZT20-23 10.53889 10.53889 10.53889