title: Add labels as percentages instead of counts on a grouped bar graph in seaborn
body: <p>I have a categorical dataset which I am plotting a bar graph using seaborn. However I am unable to add labels on top of bars in percentage value. Here is how the dataset looks like:</p>
  <pre><code>import pandas as pd
  
  #create DataFrame
  df = pd.DataFrame({'Day': ['Mon', 'Tue', 'Wed', 'Thur', 'Fri',
                             'Mon', 'Tue', 'Wed', 'Thur', 'Fri'],
                     'Customers': [44, 46, 49, 59, 54,
                                   33, 46, 50, 49, 60],
                     'Time': ['M', 'M', 'M', 'M', 'M',
                              'E', 'E', 'E', 'E', 'E']})
  
  #view DataFrame
  df
  </code></pre>
  <p>This is the code for plotting grouped bar graph:</p>
  <pre><code>import matplotlib.pyplot as plt
  import seaborn as sns
  
  #set seaborn plotting aesthetics
  sns.set(style='white')
  
  #create grouped bar chart
  sns.barplot(x='Day', y='Customers', hue='Time', data=df) 
  </code></pre>
  <p>Now I would like to add labels on top of bars but in percentage value. Kindly help</p>