pon-de-vivaux มี 20-39% กี่เปอร์เซ็นต์?
how many 20-39% are in pont-de-vivaux?
df = pd.DataFrame(columns=['_percentage_20_39_years', 'quartier'])
df[df['quartier'] == 'Pont-de-Vivaux']['_percentage_20_39_years'].count()