word-wrapping in a markup column

[David Nalesnik]

Hi all,

This snippet leaves no space between the word-wrapped items:

 \version "2.19.82"

\markup \override #'(line-width . 10) \column {
  \wordwrap { a a a a a a a a a a a a a a a a a a a a }
  \wordwrap { b b b b b b b b b b b b b b b b b b b b }
  \wordwrap { c c c c c c c c c c c c c c c c c c }
}

Is there a way to allow lines in such a column to break if needed but
maintain even spacing between all lines?  Any help is much
appreciated, as this problem has plagued me for a long time.

Thanks,
David