Regex search for year read

Hi, I gather that I need to do something with regex for this but it makes my head spin and none of my guesses have worked. In my custom #review column, I input the days that I read something in the following format:

[First read, DD MM YYYY to DD MM YYYY]

With "first" changing accordingly. I then follow this up with my thoughts after that particular reading.

I would like to create a set of saved searches for the years that I've got this data, so that I can find all books that I finished in the year 2019, say. I can do this somewhat with the search #review:2019, but this includes books that were started in 2019 but not finished that year. And of course if I mention a year or even just a number that looks like a year in the text of a review, that will show up as well.

I'm just wondering how to phrase the search expression so that it only catches the year in the format that I use.