Construct a line graph using the data from this dataframe, where the x-axis is years and the y-axis is the columns 2015 2016 2017 2018 2019 0 5.375734 5.382185 5.354019 5.375917 5.407096

def f(dframe):
  years = dframe.columns.get_level_values(0).get_level_values(0).unique()
  fig = plt.figure()
  ax = fig.add_subplot(111)
  for col in dframe.columns:
    dframe[col].plot(kind='line', ax=ax)
  plt.xticks(years)
  plt.show()

f(df)