HMO ใดมีแผนปกติที่ 3% ในปี 2548
Which HMO has a conventional plan of 3% in 2005?
df = pd.DataFrame(columns=['hmos', 'conventional_plans', 'year'])
df[(df['conventional_plans'] == '3%') & (df['year'] == '2005')]['hmos'].tolist()