This is a helper function used by get_seifa. The function can also
be used independently if you have already downloaded one of the SEIFA index score spreadsheets
from https://www.abs.gov.au/AUSSTATS/abs@.nsf/DetailsPage/2033.0.55.0012016?OpenDocument
Usage
get_seifa_index_sheet(
  filename,
  sheetname,
  structure = c("sa1", "sa2", "lga", "postcode", "suburb"),
  year
)Arguments
- filename
 character name of temporary file when spreadsheet downloaded
- sheetname
 character name of the sheet to be imported
- structure
 character spatial structure of the data to be parsed. The spatial structure is important as the shape of the data in the ABS spreadsheets if different for some structures.
