Add data validity/regression tests (@russellpierce, #27)
Add data for 2016 and 2017. Minor changes to data from previous years to match external data sources. (@russellpierce, #30)
Update data for 2015 (@stillmatic, #16)
Import from tibble in order to get consistent behaviour regardless of whether or not tibble is attached.
Correct title in description
NEWS.mdfile to track changes to the package.