I need a count of how many times three columns (Year, Gender and Date) have
the same values.

For example Year 4, Male and In or Year 8 Male and In.

Name Year Gender 25/02/2008
Miles Anderson 4 Male IN
Phoebe Brundle 5 Female IN
Alexander Cadier 5 Male OUT
Archie Chitty 8 Male IN
Rupert Coley 7 Male IN
Charlie Davies 8 Male IN
Bertie Griffiths 6 Male IN
Harry Griffiths 8 Male IN
Arabella Harvey 4 Female OUT
Hugo Harvey 7 Male IN
Harry Herbert 8 Male IN