Add the Progress Bar, is a fairly simple and quick process.

1. Log into your Blogger dashboard and go to Layout. Click on Add a Gadget. Add the "Elements" with the Gadget "HTML/JavaScript".  You can also add to Post and Pages.

Default code:

<div class="progress">

<div class="progress-bar" role="progressbar" style="width: % value ;"> Title </div>

</div>

% value: Add the Percentage Value.

Title: Add your Title.