filter_criterion = (df['Delay'] > '1h') & (df['Delay'] < '2h')
late = df[filter_criterion]
print late['Name'].value_counts()

filter_criterion = (df['Delay'] > '2h') & (df['Delay'] < '3h')
late = df[filter_criterion]
print late['Name'].value_counts()

filter_criterion = (df['Delay'] > '3h') & (df['Delay'] < '4h')
late = df[filter_criterion]
print late['Name'].value_counts()

filter_criterion =(df['Delay']>'4h') &  (df['Delay'] < '5h')
late = df[filter_criterion]
print late['Name'].value_counts()