condition mean min max ZT0-3 18.293016666666666 13.2426 23.0355 ZT4-7 9.694980000000001 9.694980000000001 9.694980000000001 ZT8-11 13.082650000000001 13.082650000000001 13.082650000000001 ZT12-15 19.2402 17.7013 20.7791 ZT16-19 16.943649999999998 16.943649999999998 16.943649999999998 ZT20-23 21.99305 21.99305 21.99305