I am using R-Studio to plot productivity (TFP) growth in the German manufacturing sector over time, however, I am not sure if I do it correctly, because in one subsector, the graph shows high volatility.
The picture shows my graph. I am using this code:

So I have this table, and I need to find the inflation rate per quarter using this data.
This is Econometrics, so I believe the formula that I have to use is this:
Inflation rate=(CPI_previous-CPI_current/CPI_current
This has to be done in a new variable called ‘Inflation Rate’.
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