C(9,7,5) <=9

Method of construction: cyclic covering found by search program

 1  2  3  4  5  7  8
 2  3  4  5  6  8  9
 1  3  4  5  6  7  9
 1  2  4  5  6  7  8
 2  3  5  6  7  8  9
 1  3  4  6  7  8  9
 1  2  4  5  7  8  9
 1  2  3  5  6  8  9
 1  2  3  4  6  7  9