import matplotlib.pyplot as plt
import numpy as np
years = ('2010', '2011', '2012', '2013', '2014')
visitors = (1241, 50927, 162242, 222093, 296665 / 8 * 12)
index = np.arange(len(visitors))
bar_width = 1.0
plt.bar(index, visitors, bar_width, color="green")
plt.xticks(index +bar_width / 2, years) # labels get centered
plt.show()