Creating a plot with a gapped axis

I used the plotrix package to add an axis break to a grouped bar plot.

R Studio notes: https://rstudio-pubs-static.s3.amazonaws.com/235467_5abd31ab564a43c9ae0f18cdd07eebe7.html

Artificially grouping bars to create a grouped bar plot with an axis break: https://stackoverflow.com/questions/24202245/grouped-barplot-with-cut-y-axis

My final code: https://github.com/eimd-2019/NIX-project/blob/master/scripts/Population-versus-Year%20Graph.R