This image shows the current inventory in the SPR -

https://www.spr.doe.gov/dir/images/img2.jpg

You can use the Wayback Machine at archive.org to look at how it looked like in the past. For example, https://web.archive.org/web/202201/https://www.spr.doe.gov/d...

Note that it is mostly Sour oil that is being moved off the SPR. Because that is the more useful type. So you might consider that 200-250mbbl of Sweet oil in the SPR is less-useful and counting the whole 400+mbbls is like counting apples and oranges together and saying you have X amount of fruit.