samdo,
<!DOCTYPE html>
<html>
<head>
<title>Untitled</title>
<meta charset="utf-8">
<style type="text/css">
</style>
<script>
document.addEventListener('DOMContentLoaded', ready);
function ready()
{
const options = {
increment: 1000,
different: 19000,
basic: 8000,
delay: 0,
differentDelay: 1000,
elem: document.querySelector('.box')
};
const random = (increment, different) => increment + Math.random() * different | 0;
const loop = () => {
options.elem.innerHTML = options.basic;
document.querySelector('.bx').innerHTML = options.basic * 1.008|0;
options.basic += random(options.increment, options.different);
setTimeout(loop, random(options.delay, options.differentDelay))
}
loop()
}
</script>
</head>
<body>
<div class="box"></div>
<div class="bx"></div>
</body>
</html>