Recently, with the changes to the top bar, the review queue got new functionality. Instead of displaying numbers when there were tasks, the queues were given trigger points and a red indicator would pop up any time there were as many or more items in the queue than that trigger point. You can read more about it in this related question: How does the review-needed indicator work exactly?
In my answer to that question, I noted that I was concerned that a trigger of fifty items in the close vote queue was something unattainable by most small sites and that if there weren't users checking the queues without being prompted to do so, some close-worthy questions would fail to be closed. This number was reduced to twenty but even that seems high for some of the sites I use.
I noticed recently that I have ten close votes/and several close reviews that aged away on Cooking since the change to the top bar and it made me wonder whether I was simply really crappy at close voting or whether this was a symptom of not sufficiently notifying users when there were items in the close vote queue... or something else, like low reviewing behavior on the site.
An absolute comparison of review tasks before and after the change is probably going to be a good indicator of whether the review queues are getting the same amount of attention after the indicator change than before it.
So, a way to see how many close vote reviews were done by users compared to how many items were put into the close review queues would probably be helpful in this.
This may be tangential to the question relating to the review indicator but it is additional information that I would find helpful in looking into this data.
Knowing how many close votes have aged away over time may help with this, though I understand that this data may not be able to attribute this to whether the question was fixed, wasn't really close-worthy, or other variables. That said, I think that if a question received three or more votes to be closed over time (including some aging away in the interim), that would be a good sign that it was likely a question that should have been closed.
Is there a way to see which questions attracted more than three close votes and then ended up not getting closed due to the votes aging away?