condition mean min max ZT0-3 13.482600000000001 13.482600000000001 13.482600000000001 ZT4-7 6.04851 6.04851 6.04851 ZT8-11 10.824449999999999 10.824449999999999 10.824449999999999 ZT12-15 15.2151 15.2151 15.2151 ZT16-19 18.478949999999998 18.478949999999998 18.478949999999998 ZT20-23 18.630899999999997 18.630899999999997 18.630899999999997