condition mean min max ZT0-3 18.953191 18.953191 18.953191 ZT4-7 24.1639635 24.1639635 24.1639635 ZT8-11 20.8157855 20.8157855 20.8157855 ZT12-15 18.708185999999998 18.708185999999998 18.708185999999998 ZT16-19 21.715960000000003 21.715960000000003 21.715960000000003 ZT20-23 20.2842045 20.2842045 20.2842045