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 line_graph(dataframe):
  fig = plt.figure()
  ax = fig.add_axes([0,0,1,1])
  ax.plot(dataframe.columns, dataframe.iloc[0])
  ax.set_xlabel('years')
  ax.set_ylabel('columns')
  ax.set_title('line graph')