How to find out how much customers uses the product comparison feature?

SELECT
(SELECT COUNT(DISTINCT customer_id) FROM catalog_compare_item)
/
(SELECT COUNT(*) FROM customer_entity)
* 100 as '%'

In my case:

So, the product comparison function is used only by 0.04% of registered customers of the store.
Also, the comparison feature is used by some part of anonymous visitors.

See also:

• How to find out how much customers uses wishlists?
• How to find out the most active wishlist users in your store?