IIRC it was a 2018 change in the calculation methodology. How they account for geographic variation and how they account for quality change over time, possibly among other things. So those might not be directly comparable numbers.
That change in CPI price level does not show up if you look at y-o-y inflation. I assume they back-calculated the 2017 (and a few more years) numbers with the new methodology to do inflation calculations, but maybe actual price level data is harder to find to make a graph with?
IIRC it was a 2018 change in the calculation methodology. How they account for geographic variation and how they account for quality change over time, possibly among other things. So those might not be directly comparable numbers.
That change in CPI price level does not show up if you look at y-o-y inflation. I assume they back-calculated the 2017 (and a few more years) numbers with the new methodology to do inflation calculations, but maybe actual price level data is harder to find to make a graph with?