สหรัฐอเมริกาชนะในปีใดด้วยคะแนนรวม 278 คะแนน?
What year did the United States win with a total of 278?
df = pd.DataFrame(columns=['year_s__won', 'country', 'total'])
df.loc[(df['country'] == 'United States') & (df['total'] == '278')]['year_s__won']