Extension for Mageto 1.x. It provides Scroll Depth plugin for Google Analytics.

Read more about Scroll Depth plugin at http://scrolldepth.parsnip.io/.

Go to store backend. Tnen menu System > Configuration > Templates-Master > Google Analytics. Select Yes for option Enable plugin under section Scroll Depth plugin.

You can set additional options to plugin by using setting Plugin options.

Example is below (http://prnt.sc/bxp41r)

Such settings generates follow code:

<script type="text/javascript">
    jQuery(function() {
        jQuery.scrollDepth({
            elements: ['.footer-container']
        });
    });
</script>