validate_apportion_data.RdValidates apportionment data input into the API functions.
validate_apportion_data(apportion_data)
Validates by the following criteria:
Columns include index_offence_group, year_ending, and number_reoffences.
Warns if there are more than one year_ending values as only the closest will be selected.
Ensures there isn't a reoffence_group column.
Warns if there are more than one numeric column as summaries might be odd.
Warns if reoffence groups outside those accepted are input, as these will not be counted.
Ensures number_reoffences is numeric.
Ensures the user_data is within the scope of the latest data in the package.