Find supporting evidence (literature reviews) that:
(1) World GDP (World economy) and export and import shares of India have a positive correlation. i.e World GDP increased both exports and import shares of India.
(2) World GDP (World economy) and export and import shares of USA have a positive correlation. i.e World GDP increased both exports and import shares of USA.
(3) GDP (of India) and export and import shares of India have a positive correlation. i.e GDP increased both exports and import shares of India.
(4) GDP (of USA) and export and import shares of USA have a positive correlation. i.e GDP increased both exports and import shares of USA.