JSFiddle - React, Tailwind, and code Playground

HTML

<h1>Results</h1>
<ol>
  
</ol>
<p></p>

JavaScript

let Counter = [0, 0, 0, 0, 0, 0];

for(let i = 0; i < 1000000; i++) {
	let randomNumber = Math.floor(Math.random() * 6) + 1;
  
  switch(randomNumber) {
  	case 1:
    	Counter[0]++
      break;
    case 2:
    	Counter[1]++
      break;
    case 3:
    	Counter[2]++
      break;
    case 4:
    	Counter[3]++
      break;
    case 5:
    	Counter[4]++
      break;
    case 6:
    	Counter[5]++
      break;
  }
}

let list = '';

for(let i = 0; i < Counter.length; i++) {
	list += `<li>${Counter[i]}</li>`
}
document.querySelector('ol').innerHTML = list;

var findMaxDiff = function(arr){
    var diffs = [];
    for(var i = 1; i < arr.length; i++){
        for(var j = 0; j < i; j++){
            if(arr[i] > arr[j]){
                diffs.push(arr[i]-arr[j]);
            }
        }
    }
    return Math.max.apply( Math, diffs );
}
 
document.querySelector('p').innerHTML = `The maximum difference of occurence between highest and lowest occured number is <b>${findMaxDiff(Counter)}</b>`;