values:
  1959-01-01:
    value: 0.09
  1960-01-01:
    value: 0.08
  1961-01-01:
    value: 0.06
  1970-01-01:
    value: null
metadata:
  unit: /1
  reference:
    href: https://www.ipp.eu/outils/baremes-ipp/