import matplotlib.pyplot as plt

years = [1950, 1955, 1960, 1965,
         1970, 1975, 1980, 1985, 1990, 1995, 2000, 2005, 2010, 2015]

pops = [2.5, 2.7, 3.0, 3.3, 3.6, 4.0, 4.4,
        4.8, 5.3, 5.7, 6.1, 6.5, 6.9, 7.3]

deaths = [1.2, 1.7, 1.8, 2.2, 2.5,
          2.7, 2.9, 3, 3.1, 3.3, 3.5, 3.8, 4.0, 4.3]

plt.plot(years, pops, color=(255/255, 100/255, 100/255))
plt.plot(years, deaths, '--',  color=(.6, .6, 1))

plt.ylabel("Population in billions")
plt.xlabel("Year")
plt.title("Population Growth")
plt.show()