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:
| Sport | Body | Year | Event type | Location | Nations |
| --- | --- | --- | --- | --- | --- |
| Aquathlon | CMAS | 2009 | World Cup | Not known | Not known |
| Finswimming | CMAS | 1976 | World Championship | Hanover , Germany | Not known |
| Free-diving | AIDA | 1996 | World Championship | Nice , France [ citation needed ] | Not known |
| Spearfishing | CMAS | 1957 | World Championship | Mali Losinj , Yugoslavia | Not known |
| Sport Diving | CMAS | Before 2011[ citation needed ] | World Cup | Not known | Not known |
| Underwater football | MUC | not known | not known | not known | not known |
| Underwater hockey | CMAS | 1980 | World Championship | Vancouver , Canada | 5 |
| Underwater Ice Hockey | Not known | 2007 | World Cup | Weissensee , Austria | 8 |
| Underwater orienteering | CMAS | 1973 | World Championship | Lokve, Yugoslavia | Not known |
| Underwater photography | CMAS | 1985 | World Championship | Genoa , Italy | Not known |
| Underwater rugby | CMAS | 1980 | World Championship | Mullheim, Germany | Not known |
| Underwater target shooting | CMAS | 1999 | World Championship | Not known | Not known |
| Underwater video | CMAS | 2010 | World Championship | Fuerteventura , Canary Island , Spain | 7 |
Question:
What nations participated in 2007?
Answer:
8.0