The one way I figured out to do this was to add html code for an extra linebreak and a space into the title, which would look like the following for you:
title = 'Median Income<br> '
For a smaller gap, use the following to turn the space into a superscript (or subscript, if the gap is to be above the title):
title = 'Median Income<br><sup> </sup>'
It might look even nicer if you put a line break between the two words, as follows: