instruction: From the passage identify the years in which major events happened in Icahn’s business career. Display the results in comma separated format.
context: In 1961, Icahn began his career as a stockbroker for Dreyfus Corporation. In 1963, he became an options manager for Tessel, Patrick & Co. and then he moved to Gruntal & Co.
  
  In 1968, with $150,000 of his own money and a $400,000 investment from his uncle, M. Elliot Schnall, Icahn bought a seat on the New York Stock Exchange and formed Icahn & Co., which focused on risk arbitrage and options trading.
  
  In 1978, in his first takeover attempt, he took a controlling stake in Tappan and forced the sale of the company to Electrolux, making a profit of $2.7 million, or doubling his investment. In 1979, he acquired Bayswater Realty & Capital Corporation. In 1983, he acquired ACF Industries and in 1985 he sold those shares to Phillips Petroleum, making a $50 million profit.[failed verification]
  
  In 1985, by pooling his funds with investor funds and funds borrowed from banks, Icahn acquired 50% of Trans World Airlines, and he completely acquired the company in a leveraged buyout in 1988. Icahn systematically sold TWA's assets to repay money he owed, which was described as "asset stripping" and made him known as a "corporate raider". In 1991, he sold TWA's London routes to American Airlines for $445 million. Icahn made a $469 million profit, and left TWA with $540 million in debt. He formed lowestfare.com to sell TWA tickets and acquired portions of Global Leisure Travel from Ramy El-Batrawi.
  
  In October 1986, Icahn launched an unsuccessful $8 billion hostile takeover for 89% of U.S. Steel; the bid was dropped in January 1987. In 1991, he sold his stake in the company for $1 billion, making a $200 million profit.
response: 1961, 1963,1968, 1978, 1983, 1985, 1986, 1988, 1987, 1991