JSFiddle - React, Tailwind, and code Playground

HTML

<pre id="result"></pre>

JavaScript

var str2 = '37 39 53 68 75 3 49 61 62 68 23 25 28 30 75 31 35 41 65 66 9 15 24 39 41 11 29 36 58 67 3 50 57 58 60 2 14 21 28 55 5 35 37 41 66 21 31 43 56 60 11 37 46 64 68 2 32 35 50 59 16 29 46 48 55 3 20 34 58 67 3 16 52 54 61 17 26 35 46 62 21 24 25 40 43 16 25 27 29  34 25 45 51 53 73 18 28 33 36 42 25 34 55 70 71 7 12 20 24 59 1 8 54 69 72 3 26 45 58 73 29 31 51 60 64';
var result = document.getElementById('result');

counts(str2).forEach(function(v){ 
    result.innerHTML += v.join(",")+"\n"
})

function counts(str2) {
    var res2 = str2.split(" ").map(function (v) {
        return +v
    }).sort(function (a, b) {
        return a - b;
    });
    var unique = [];
    for (var i = 0; i < res2.length; i++) {
        if (res2[i] !== res2[i - 1]) unique.push([findOccurrences(res2, res2[i]), res2[i]]);
    }
    return unique.sort(function (a, b) {
        return b[0] - a[0]
    })

    function findOccurrences(arr, val) {
        return arr.filter(function (v) {
            return v === val
        }).length
    }
}