data.groupby(['Year', 'Full_half']).size().plot(kind='bar', fontsize=16, title='Number of finishers each year') data.groupby(['Year', 'Full_half']).size()
Year Full_half 2013 HM 15340 MA 4897 2014 HM 16668 MA 5318 2015 HM 9787 MA 4667 2016 HM 13757 MA 5560 2017 HM 15908 MA 5991 dtype: int64