The number to the far left in the sequence of numbers (in this example '11') indicates the Major version number.
Customers who have a Gold Subscription do not have to pay an Upgrade Fee, regardless of which version they are currently using.
There is no Fee if you are upgrading within a major version, i.e. 11.0.0 to 11.0.1 but there is a Fee if you are upgrading from one major version to another i.e. 10.x.x to 11.0.1.
If your upgrade requires a Fee, then before you download and install any files, email email@example.com, for a quote.
After your upgrade Fee has been received, you will be emailed a new license file to use for your new version, including instructions on how to integrate this into your upgraded version.