What is the default value for a plugin's `sortOrder`?

[dossy]

Is there an existing issue for this?

• I have searched the existing issues

What's missing?

In src/pages/development/components/plugins.md, it says:

The following elements are optional:

• plugin sortOrder. Plugins that call the same method run them using this order.
• plugin disabled. To disable a plugin, set this element to true. The default value is false.

What is the default value for sortOrder?