บริษัทใดมีการลดลงของรายได้มากที่สุดจากปี 2021 ถึง 2022?
 Which companies have the biggest revenue declines from 2021 to 2022?
revenue_change_2021_2022 = pd.merge(data_2021[['Company', 'Revenue']], data_2022[['Company', 'Revenue']], on='Company', suffixes=('_2021', '_2022'))
revenue_change_2021_2022['Revenue Change'] = revenue_change_2021_2022['Revenue_2022'] - revenue_change_2021_2022['Revenue_2021']
most_decrease_revenue_company = revenue_change_2021_2022[revenue_change_2021_2022['Revenue Change'] == revenue_change_2021_2022['Revenue Change'].min()]