Table 1:

Frequency and rate of concussion in National Hockey League (NHL) regular season games per 100 players (1997–2004)

NHL regular season	Frequency of concussion	Players, no.	Rate of concussion per 100 players
1997–98	56	1218	4.6
1998–99	88	1249	7.0
1999–00	66	1347	4.9
2000–01	109	1419	7.7
2001–02	96	1470	6.5
2002–03	72	1457	4.9
2003–04	72	1459	4.9
Overall	559	9619	5.8