For this to work, you need to compile unbound from source, explained here.
My unbound configuration files (without the additional munin configuration) are listed here.
The installation notes (README) and script can be found here. You need to make some modifications to the install script to reflect the actual IP and domain of your system, so read the README first.
Your system needs to be running unbound and munin for several days / weeks, before the resulting graphs become meaningful.
result:
