Custom Query (Get Average)

I have a table with Client IDs and amount spent. I can get a unique count of the clients and I can get a total spent. How do I get the average spent over all?

So I need to do my Total divided by Clients to get the average but not sure how to do that in MySQL. Been trying everything.

Screen Shot 2020-02-06 at 11.57.19 AM696×406 55.1 KB

SELECT
	COUNT(DISTINCT cost_clientid) AS Clients, 
	SUM(cost_amount) AS Total
FROM
	p_skillshighway_costs