apply_discounting       Calculate the discounted (net present value) of
                        costs or effects
data_model_output_sick_sicker
                        Example model output for the sick-sicker model
depreciation_interest   Annual depreciation + interest for medical
                        equipment
df_cpi_combined         Consumer Price Index (CPI) data from CBS
df_fp                   Job vacancy data from CBS
df_ppp                  Purchasing Power Parity (PPP) data from OECD
df_ref_prices           Complete data of reference values from the
                        costing manual
friction_period         Friction period lookup (days/weeks; 1-year or
                        5-year average)
nl_ppp                  A function to obtain the Dutch PPP factor
                        values in International Dollar (INT$)
nl_price_index          A function to calculate the Consumer Price
                        Index (CPI) for a given year range.
nl_ref_prices           A function to download the Reference prices of
                        the Dutch Costing Manual for one or multiple
                        years
pretty_price            A function to write pretty prices in 'bookdown'
                        reports
