If we want to show that he didn't lower prices from day 1 (January 20 or January), and that we can show that. (I like your YOY graph) But the ad doesn't do that.
The reason they chose "since 2022" is, I think, because (a) it makes the numbers bigger in the ad and (b) the Republicans controlled the House beginning January 2023 (i.e. since the end of 2022), so they can hang all this on that. It's flimsy as heck given the Dems controlled the presidency and the Senate in 2023-2024,. I shudder to think what the counter-ads are going to look like.
Food: https://data.bls.gov/timeseries/CUSR0000SAF1
January: 335.671, July (latest): 339.652, up 1.19%, annualized: 2.39%
Food at home (i.e. groceries): https://data.bls.gov/timeseries/CUSR0000SAF11
January: 311.178, July (latest): 312.659, up 0.48%, annualized: 0.95%
Food away from home: https://data.bls.gov/timeseries/CUSR0000SEFV
January: 375.532, July (latest): 383.808, up 2.20%, annualized: 4.46%
To see monthly changes or year-over-year changes or 3-month rolling averages, including graphs, one can click on More Formatting Options at the top right of the screen and then check the checkboxes: 1-month percent change, 3-month percent change, and so on.
As for prices overall:
CPI:
http://data.bls.gov/timeseries/CUSR0000SA0
January: 319.086, July (latest): 322.132, up 0.95%, annualized: 1.92%
(a mild increase, thanks to a drop in energy prices which partly offset the increases in other prices)
Energy:
https://data.bls.gov/timeseries/CUSR0000SA0E
January: 282.481, July (latest): 275.044, down 2.63%
To complement your year-over-year graphs, here are my 3-month and 1-month changes graphs for a little more "recency". (I don't show my core CPI graphs because we won't win any ad wars talking about core prices. But one can see those at:
https://www.democraticunderground.com/?com=view_post&forum=1014&pid=3511525
(it was a hot core CPI report and the core CPI graphs look awful)
I'm repeating your year-over-year graph so they are all together:
CPI:


HAPPY PCE DAY in about 3 hours!!