9-month résumé gap, advice? - 21 weeks in

I have been out of work for 9 months and worry about the gap. It has been a long 21 weeks. I am not sure how much to explain.

I was hired after a 9-month gap. The manager said the skills test mattered more than the dates.

I listed the volunteering and course under the same dates and kept the explanation to a sentence in the cover letter.