Block visibility settings

Hi, it’s Intern

I’m trying to keep track of how much the website is actually used, and thought it would be a good idea to see how many are logged in at any moment. I know there’s a block for this, but I thought it might be a good idea to only show this block for administrators and editors, and try it out for a week before making it public. I'm not sure of how to do this – could you do it?

//Intern