Task: Question Generation
Input (English): Through most of Shell's early history, the Shell Oil Company business in the United States was substantially independent with its stock being traded on the NYSE and with little direct involvement from the group's central offices in the running of the American business. However, in 1984, Royal Dutch Shell made a bid to purchase those shares of Shell Oil Company it did not own (around 30%) and despite opposition from some minority shareholders, which led to a court case, Shell completed the buyout for a sum of $5.7 billion.
Output (English): In what year did Royal Dutch Shell make a bid to purchase approximately 30% of Shell Oil Company's shares?