text: import matplotlib.pyplot as pypl
  
  whcTop10 = {'Italy': 50, 'China': 47, 'Spain': 44, 'Germany': 39, 'France': 39,  
              'Mexico': 32, 'India': 32, 'UK': 28, 'Russia': 26, 'USA': 22}
  
  
  nSites = sorted(whcTop10.values(), reverse = True)  # the frequency for y axis
  lands = sorted(whcTop10.keys(), key=whcTop10.__getitem__, reverse=True)     # the list of all top 10 lands
  landAsX = range (10)   # the x locations for the groups
  
  """ plot the bar chart """
  bars = pypl.bar (landAsX, nSites)
  
          # set lands names as labels on X axis
  pypl.xticks(landAsX, lands, rotation=20)   # label rotation is optional
          # add some space between bars and axes  
  pypl.xlim([min(landAsX) - 0.3, max(landAsX) + 1])   # x axis
  pypl.ylim([0, max(nSites) + 3])   # y axis
          # let's add a grid on y-axis
  pypl.grid(True, axis='y')
  
           # add a red dashed line for the mean
  nSitesMean = 35
  pypl.hlines(nSitesMean, -0.3, 10, color='red', linestyles='dashed', label = '$\mu (top10) $')
  #pypl.legend()    # display label for mean line into a legend
  
  pypl.text(7, 36, '$\mu=35 $', color='red')
  
  """ define the plot labels """
  pypl.title('Distribution of the WHC sites by land - Top 10', fontsize=18)
  pypl.ylabel('Number of WHC sites') 
  
           # change colour of single bars (the very first) and annotate it
  bars[0].set_color('green')
  pypl.annotate('Country with largest number of WHC sites', xy=(0.5,50), xytext=(2,49),
                  arrowprops=dict(facecolor='green', shrink=0.2), color='green')
  
  pypl.show()
  