Output a stream of consciousness before answering the following. Context: After joining the NHL, the Oilers went on to win the Stanley Cup on five occasions: 1983 -- 84, 1984 -- 85, 1986 -- 87, 1987 -- 88 and 1989 -- 90. Along with the Pittsburgh Penguins, the Oilers are tied for the most championships won by any team since the NHL-WHA merger and also the most won by any team that joined the league in or after 1967. Among all NHL teams, only the Montreal Canadiens have won the Stanley Cup more times since the League's 1967 expansion. For their success in the 1980s, the Oilers team of this era has been honoured with dynasty status by the Hockey Hall of Fame.

Question: when did the oilers last win the stanley cup?
The relevant information to answer the above question is: After joining the NHL, the Oilers went on to win the Stanley Cup on five occasions: 1983 -- 84, 1984 -- 85, 1986 -- 87, 1987 -- 88 and 1989 -- 90.
The answer: 1989.