Please read the following table in Markdown format and then answer the question according to the table. Table cells in one row are seperated by '|', and different rows are seperated by '
'.

Table:
| Pick # | Player | Position | Nationality | NHL team | College/junior/club team |
| --- | --- | --- | --- | --- | --- |
| 123 | Paul Ames | Defence | United States | Pittsburgh Penguins | Billerica High School (USHS-MA) |
| 124 | Joe Reekie | Defence | Canada | Hartford Whalers | North Bay Centennials (OHL) |
| 125 | Greg Evtushevski | Right Wing | Canada | New Jersey Devils | Kamloops Blazers (WHL) |
| 126 | Bob Pierson | Left Wing | Canada | Detroit Red Wings | London Knights (OHL) |
| 127 | Tim Burgess | Defence | Canada | Los Angeles Kings | Oshawa Generals (OHL) |
| 128 | Cam Plante | Defence | Canada | Toronto Maple Leafs | Brandon Wheat Kings (WHL) |
| 129 | Iain Duncan | Left Wing | Canada | Winnipeg Jets | North York Rangers (OJHL) |
| 130 | Terry Maki | Left Wing | Canada | Vancouver Canucks | Brantford Alexanders (OHL) |
| 131 | Jeff Hogg | Goaltender | Canada | Calgary Flames | Oshawa Generals (OHL) |
| 132 | Craig Mack | Defence | United States | Quebec Nordiques | East Grand Forks High School (USHS-MN) |
| 133 | Steve Orth | Centre | United States | New York Rangers | St. Cloud State University (WCHA) |
| 134 | Christian Ruuttu | Centre | Finland | Buffalo Sabres | Pori (Finland) |
| 135 | Dwaine Hutton | Centre | Canada | Washington Capitals | Kelowna Wings (WHL) |
| 136 | Sean Toomey | Left Wing | United States | Minnesota North Stars | Cretin-Derham Hall High School (USHS-MN) |
| 137 | Jim Sprenger | Defence | United States | New York Islanders | Cloquet High School (USHS-MN) |
| 138 | Vladislav Tretiak | Goaltender | Soviet Union | Montreal Canadiens | Moscow CSKA (USSR) |
| 139 | Scott Birnie | Rignt wing | Canada | Chicago Black Hawks | Cornwall Royals (OHL) |
| 140 | Dale Derkatch | Centre | Canada | Edmonton Oilers | Regina Pats (WHL) |
| 141 | Bob Mormina | Right Wing | Canada | Philadelphia Flyers | Longueuil Chevaliers (QMJHL) |
| 142 | Ian Armstrong | Defence | Canada | Boston Bruins | Peterborough Petes (OHL) |
Question:
how many centre position players are there?
Answer:
4