Would like to create an array with number of matches for specific regexs

Would like to create an array with number of matches for specific regexs: So if january was found 5 times , feb 3 the table would be: monthFound=[5,3......]

function findMonth(){
        var fpath='log.txt';
        var monthFound=[]
              fs.readFileSync(fpath).toString().split('\n').forEach(function(line) 
              {
                      var regExpressions1=[/-jan-/,/-feb-/,/-mar-/,/-apr-/,/-may-/,/-jun-/,/-jul-/,/-aug/,/-sep-/,/-oct-/,/-nov/,/-dec-/];

                      for (var i = 0; i<regExpressions1.length;i++) 
                      {
                        var idx = line.match(regExpressions1[i]);
                        if (idx !== null) {
                            y++;                             
                          }    
                       }
            }); 
}

via plska