How to plot bar chart grouped by secondary variable in R?

Question

I have a dataset with a set of KPIs for each year:

Using RI want to plot the KPIs in a bar chart in such a way that the bars are grouped by KPIs like this:

The above chart is very easy to obtain in Excel, but I am struggling to achieve the same result in R using ggplot2 library. This is my attempt:

    coeffs <- read.csv("all_coefficients.csv")

ggplot(data = coeffs %>% gather(Variable, Coefficient, -year), 
       aes(x = year, y = Coefficient, fill = Variable)) + 
    geom_bar(stat = 'identity', position = 'dodge') +
  theme(legend.position="bottom")

but the output is:

How can I group the bars by KPIs and not by year and assign a different colour to each year's bar?

Answer 1

Changing to

aes(x = Variable, y = Coefficient, fill = factor(year))

should give you what you want.