How to change a font size within a plot figure

I can’t figure out how to change the objects font size on y ticks. Any suggestions?
Here is the screenshot:

 objects = (maternal_mortality['Country Name'])
 y_pos = np.arange(len(objects))
 width = .5

 year_1990 = maternal_mortality['1990']
 year_2015 = maternal_mortality['2015']


 plt.barh(y_pos +width, year_1990, align='center', alpha=0.5,  label='1990')
 plt.barh(y_pos +width, year_2015, align='center', alpha=0.5, label='2015')



 plt.yticks(y_pos, objects)
 plt.xlabel('Percentage')
 plt.title('Maternal Death Worldwide in 1990 vs 2015')

 plt.legend()
 plt.figure(figsize=(10,10))

 plt.show()