htop - show I/O wait percentage

Is there a way to show I/O wait percentage in htop? I can't find a way how to enable this. On the following link there is an example of the functionality I need (the "Avg:" row): http://www.concept47.com/austin_web_developer_blog/sysadmin/something-cool-i-learned-about-htop/ But in my version of htop 2.0.2 I don't know how to enable this. I know that I can get this info from iotop and similar tools but I would like to have this info in htop.

Press F2, go to AVailable Meters, then select CPU Average or just CPU ( depending on version/distribution you are using. Add it to your view and place it where you like.
In the configuration dialog, navigate to the section you have added ( Left column / Right column ) and hit Space to toggle through the available types. The type you are looking for is Text.

Update

Additionally you might have to enable Detailed CPU time (System/IO-Wait/Hard-IRQ/Soft-IRQ/Steal/Guest) option which can be found in the F2 menu, then Display options.

Result: