javascript - find percentage of page height jquery -

i trying write code div telling user how far has scrolled down page. here code:

$(document).scroll(function(){  var fullheight = $(this).height();  var currentheight = $(this).scrolltop();  var percentageofpage = currentheight/fullheight;  percentageofpage = percentageofpage.tofixed(2);  var t = $("#t"); t.html("you " + percentageofpage + " down page." );   }); 

fiddle
code works how should: writes out percentage how far user has scrolled. stops @ .67 or .69. why that? want go way 1. also, how can display percentage, 60%, instead of decimal, .6? here page is.

addition:
how can make @ when user reaches bottom of page, message becomes: "you have reached bottom of page", instead of percentage?

$(document).on('scroll.percentage', function() {    var scrollpercent = math.round(100 * $(window).scrolltop() / ($(document).height() - $(window).height()));    // if user has reached bottom of page    // unbind scroll listener    if (scrollpercent == 100) {      $("#t").html("you have reached bottom of page.");      $(this).off('scroll.percentage');      return;    }    $("#t").html("you " + scrollpercent + "% down page.");  });

html,  body {    height: 1000px;  }  #t {    position: fixed;    top: 0;  }

<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.9.1/jquery.min.js"></script>  <div id="t"></div>