Plotting activity of the day: SWS hunger data

From (largely) quarterly SWS data on total hunger incidence (% of households who experienced having nothing to eat at least once in the past 3 months)...

...I got this trend line with a polynomial fit (order=6) superimposed. I tried reverse engineering an existing line graph online using PlotDigitizer when I had no data to work on, but it turned out to be largely inaccurate unless the data points were identifiable.