<style>
#fablProgress {
    transition: transform 0.5s cubic-bezier(0.14, 0.52, 0.4, 0.78);
    top: 60px;
    left: 0px;
    width: 100%;
    height: 10px;
    position: fixed;
  
}
#fablBar {
    width: 0px;
    line-height: 0.6em;
    margin-top: -1px;
}
#greenLine {
    display: inline-block;
    z-index: 1000;
    width: 100%;
    height: 11px;
    background-color: green;
    transition: transform 5s cubic-bezier(.14,.52,.4,.78);
}
#scrolledPerc {
    display: inline-block;
    position: relative;
    float: right;
    width: 50px;
    height: 31px;
    background-color: darkgrey;
    color: white;
    text-align: center;
    line-height: 2.0em;
    font-size: 14.5px;
    font-family: proxima-nova,Proxima Nova,Helvetica Neue,Helvetica,Arial,sans-serif;
    border-radius: 3px;
}
</style>

  <script>
function progress() {

    var scHeight = window.innerHeight;
    var scWidth = document.getElementById("content").offsetWidth;
    var elem = document.getElementById("myBar");
    var scrolled;
    var h = document.getElementById("content").offsetHeight;
    var aspect;
    
    var random = 5; 

      window.onscroll = bar;

    function bar() {
        scrolled = window.pageYOffset || document.documentElement.scrollTop;
        aspect = ((scrolled*scWidth)/(h-scHeight));
        
            elem.style.width = aspect + 'px';
          
            var per = Math.floor(aspect*100/scWidth);

            
            if (per <= 3) {
                document.getElementById("scrolledPerc").style.width = 0 + "px";
                document.getElementById("scrolledPerc").innerHTML = "";
            } else if ((4 <= per) && (per <= 100)) {
                document.getElementById("scrolledPerc").style.width = 50 + "px";
                document.getElementById("scrolledPerc").innerHTML = per + "%";
            } else if (per > 100) per = 100;
    }
};

progress();
</script>

<div id="myProgress">
  <div id="myBar">
    <div id="greenLine">