The rivalry between the Avalanche and the Red Wings was most intense from 1996 to 2002. During those seven seasons the two teams played five postseason series against each other in the Stanley Cup playoffs, with the Avalanche winning three of the series (1995-96, 4-2; 1998-99, 4-2; 1999-2000, 4-1) and the Red Wings winning two of them (1996-97, 4-2; 2001-02, 4-3). During this time frame, these two teams combined for a total of five Stanley Cup championships in seven years, the Avalanche winning twice (1995-96 and 2000-01) and the Red Wings winning three times (1996-97, 1997-98 and 2001-02). After 2002, the rivalry between the two teams began to cool down, and the two teams would not meet again in the playoffs until 2008, when the Red Wings swept the Avalanche in the Western Conference Semi-finals and went on to win the Stanley Cup. The Red Wings moved to the Eastern Conference in 2013-14 season as part of the realignment which makes the two rivals only see each other twice a year.
Question: When did Avalanche win series back to back?
Answer: 1998-99 | 1999-2000