I can't persist data when my php page is refreshed.

I expect the following code to increment the value of views each time the page is refreshed until the user closes their browser. It doesn't. Output is always "views = 1."

Code:
<?php
session_start();  
if(isset($_SESSION['views']))
    $_SESSION['views'] = $_SESSION['views'] + 1;
else
    $_SESSION['views'] = 1;
...