Photo library is organised alphabetically and numerically folders, not years

Hi,

I have recently started using Photo on my Mac and I now have 8000 approx photos/videos in the app. I have researched how to see the files by accessing the Photo Library and seeing the folder structure.

Based on what I have learned, I should have a folder in my library folder structure for 'Masters' (or Originals?) Inside this folder I should have a folder for each year (2010, 2011...)

However, I have a folder named 'Originals' and inside this I have a list of folders titled: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 and then folders titled: A, B... F. From what I can see, these folders contained my photo files which begin with the number '0', or the letter 'B' etc. So inside each of these folders is a range of photos from different years.

I have add three shots of the folders below. Does anyone know why folders are being titled and structured this way, rather than in years - and how I might correct the issue? Many thanks.