Question: How many regular seasons did the National Hokey League have up til the 1991-92 Edmonton Oilers season?

Context articles: 2003–04 Edmonton Oilers season
1991–92 Edmonton Oilers season
1988–89 Edmonton Oilers season
2007–08 Edmonton Oilers season
1985–86 Edmonton Oilers season
1973–74 Edmonton Oilers season
1986–87 Edmonton Oilers season
Paul Houck
1990–91 Edmonton Oilers season
1991–92 NHL season

The 2003–04 Edmonton Oilers season was the Oilers' 25th season in the NHL, and they were coming off a 36–26–11–9 record in 2002–03, earning 92 points, and returned to the playoffs after a one-year absence.
 The Oilers were then defeated by the Dallas Stars in six games in the opening round.
The 1991–92 Edmonton Oilers season was the Oilers' 13th season in the NHL, and they were coming off a 3rd round playoff appearance in 1990–91, losing to the Minnesota North Stars in the Campbell Conference finals.
The 1988–89 Edmonton Oilers season was the Oilers' tenth season in the NHL, and they were coming off a Stanley Cup championship after defeating the Boston Bruins the previous season, which was their fourth Stanley Cup in the past 5 seasons.
 The Oilers would finish third in the Smythe Division with 84 points, their lowest point total since the 1980–81 season.
 For the eighth consecutive season, the Oilers had five 30-goal scorers.
The 2007–08 Edmonton Oilers season began on October 4, 2007.
 It was the Oilers' 36th season, 29th in the National Hockey League.
 This season also marks the debut of the Edmonton Oil Kings, a Western Hockey League expansion team purchased by the Oilers after the team spent several years attempting to buy and relocate any existing WHL team to the Alberta capital.
The 1985–86 Edmonton Oilers season was the Oilers' seventh season in the NHL, and they were coming off back to back Stanley Cup Championships.
 Edmonton would win the Presidents Trophy, as they finished with 119 points, which was a league high and tied the franchise record which was set in the 1983–84 season.
 The Oilers won the Smythe Division for the 5th consecutive season, and were heavy favourites to win their third-straight Stanley Cup.
 It was also the fifth consecutive season in which they scored at least 400 goals.
 However, the Oilers were defeated by the Calgary Flames in the second round.
The 1973–74 Edmonton Oilers season was the second season of operation of the Edmonton Oilers in the World Hockey Association.
 The Oilers' qualified for the playoffs, losing in the first round to the Minnesota Fighting Saints.
The 1986–87 Edmonton Oilers season was the Oilers' eighth season in the NHL, and they were coming off a heart breaking playoff loss to the Calgary Flames the year before, ending the Oilers' bid for a third-straight Stanley Cup.
 Edmonton would win the Presidents' Trophy, as they finished with 106 points, and win their sixth straight Smythe Division title.
 There was no postseason upset this year, as Oilers defeated the Philadelphia Flyers in the Final to win their third Stanley Cup in four years, although the Flyers did push the Finals series to seven games.
Paul Houck (born August 12, 1963 in Vancouver, British Columbia) is a former ice hockey player.
 He had a successful college career with the University of Wisconsin between 1981 and 1985, and was named a Western Collegiate Hockey Association Second Team All-Star in 1983, as well as earning a spot on the National Collegiate Athletic Association Championship All-Tournament team.
 He was selected 71st overall by the Edmonton Oilers in the 1981 NHL Entry Draft, and traded to the Minnesota North Stars in 1985.
 Houck played 16 National Hockey League games for the North Stars between 1985 and 1988, scoring one goal and two assists while spending most of his career in the minor leagues.
 He played two seasons in the Nederlands between 1989 and 1991 before retiring.
 His son, Jackson Houck, was drafted 94th overall by the Edmonton Oilers in the 2013 NHL Entry Draft.
 Paul, of the 1981 NHL Entry Draft, and his son, of the 2013 NHL Entry Draft, become the first father-and-son tandem drafted by the Edmonton Oilers in the team's history.
The 1990–91 Edmonton Oilers season was the Oilers' 12th season in the NHL, and they were coming off of their 5th Stanley Cup in the last 7 seasons, after defeating the Boston Bruins in the Stanley Cup finals.
 The Oilers would finish the season with a 37–37–6 record for 80 points, their lowest point total since 1980–81, and Edmonton would score a franchise low 272 goals, however, the Oilers would set a franchise record for fewest goals against, with 272.
 After a 2–11–2 start to the season, the Oilers would rebound, and finish 3rd in the Smythe Division and continue their playoff streak of making the playoffs every year they've been in the NHL.
The 1991–92 NHL season was the 75th regular season of the National Hockey League.
 The Pittsburgh Penguins repeated as Stanley Cup champions, winning a best of seven series four games to none against the Chicago Blackhawks.