title: Plot sample average GDP over time
body: <p>I'm trying to plot a graph from a table.</p>
  
  <p><a href="https://i.stack.imgur.com/KGjZ7.png" rel="nofollow noreferrer">df_GDP</a></p>
  
  <p>and here is the code I tried to plot a graph.</p>
  
  <pre><code># Plot sample average GDP over time
  x = df_GDP.columns[3:]
  y = df_GDP.mean()
  plt.plot(x,y)
  plt.title('Global Mean GDP(USD in 2000, adj. for inf.)')
  plt.xlabel('Year (C.E.)')
  plt.ylabel('GDP mean')
  plt.show()
  </code></pre>
  
  <p>And this is what I got:</p>
  
  <pre><code>ValueError: x and y must have same first dimension, but have shapes (58,) and (55,)
  </code></pre>
  
  <p>What am I doing wrong?</p>