Its what's known as your author score. Over a number od days/weeks, it will rise. Once it's at a decent level, it may fluctuate, go up and down.
The highest it can reach is #100. It's based on different factors, such as great content, unique hubs, your readership, whether it's external etc, whether readers rate your hubs up or not. many things.
If you check out the FAQs, you'll find what you're looking for, in more detail.