I am Moment.js to format the datetime in the first column of my datatable to include month, day, and year. I'm additionally trying to add a dropdown (select) filter at the top of my table that will sort by year. The code below pulls out all of the unique datetimes, but how can I get it so it pulls only the unique years?

$(document).ready(function() {
            $.fn.dataTable.moment( 'MMM DD, YYYY' );
            var table = $('#outreach').DataTable( {
                "order": [[0, "desc"]],
                "lengthMenu": [[10, 25, 50, -1], [10, 25, 50, "All"]],
                "language": {
                    "zeroRecords": "No entries found. Please adjust your search parameters.",
                    "info": "Showing page _PAGE_ of _PAGES_",
                    "infoEmpty": "No entries found"
                },
                "stateSave": true,
                "stateDuration": 3600,
                "initComplete": function() {
                    this.api().columns([0]).every(function() {
                        var column = this;
                        var select = $("#outreach-year-filter");
                        column.data().unique().sort().each(function (d, j) {
                            console.log(d, j)
                            select.append('<option value="'+d+'">'+d+'</option>')
                        });
                    });
                }
            });