What percent of the country's oil refineries does Rockefeller own?

John D. Rockefeller, through Standard Oil, once controlled a significant portion of the United States' oil refining capacity, peaking at around 90%. However, Standard Oil was dissolved in 1911 due to antitrust laws, resulting in the formation of several independent companies. Today, no single entity, including those that emerged from Standard Oil, owns such a vast percentage of the country's oil refineries. The exact percentage of oil refineries owned by contemporary companies varies and is significantly lower than Rockefeller's historical control.