Do you know where your pages are? Sounds like a stupid question and one that should not have to be asked but...
Hopefully you are getting full credit for all the content you've created.
There's no doubt that your HubSpot Website Grade is influenced by the number of pages that have been indexed by Google. Is there a magic number? More is better, but we see a significant jump in website grade when the total number of pages hits 200. Here are some things you can do to make sure you're number is accurate. Don't know what a Website Grade is? Get yours here.
Is all your content under the umbrella of a single domain? Make sure that if you have a blog/forum/e-commerce site that it is under the umbrella of your 'flagship' domain. If you have content residing on different hosts, you should be using subdomains like blog.mysite.com, shop.mysite.com, forums.mysite.com. That way search engines will credit you for all your content.
Use Google Webmaster Tools (Now Google Search Console). Submit your sitemaps and feeds. Let them know your content is out there. Get Google Webmaster Tools tips here.
Create pages. There's no magic here. Blog, Blog, Blog. Add static pages like FAQs that link to more pages. Move downloads behind landing pages. Lacking inspiration for blogging today? Do a "best of" or "in case you missed it" post. Repurpose, Reuse, Recycle. Read Increase your content's mileage here.