Participating countries
The table shows which survey rounds each country has taken part in, from the first round in 1983/84 to the most recent round in 2017/18.
- Albania: 2013/14, 2017/18
- Armenia: 2009/10, 2013/14, 2017/18
- Austria: all rounds (1983/84–2017/18)
- Azerbaijan: 2017/18
- Belgium (Flemish): 1989/90*, 1993/94, 1997/98, 2001/02, 2005/06, 2009/10, 2013/14, 2017/18
- Belgium (French): 1985/86, 1989/90*, 1993/94, 1997/98, 2001/02, 2005/06, 2009/10, 2013/14, 2017/18
- Bulgaria: 2005/06, 2013/14, 2017/18
- Canada: 1989/90, 1993/94, 1997/98, 2001/02, 2005/06, 2009/10, 2013/14, 2017/18
- Croatia: 2001/02, 2005/06, 2009/10, 2013/14, 2017/18
- Czech Republic: 1993/94, 1997/98, 2001/02, 2005/06, 2009/10, 2013/14, 2017/18
- Denmark: all rounds (1983/84–2017/18)
- England: 1983/84, 1997/98, 2001/02, 2005/06, 2009/10, 2013/14, 2017/18
- Estonia: 1993/94, 1997/98, 2001/02, 2005/06, 2009/10, 2013/14, 2017/18
- Finland: all rounds (1983/84–2017/18)
- France: 1993/94, 1997/98, 2001/02, 2005/06, 2009/10, 2013/14, 2017/18
- Georgia: 2017/18
- Germany: 1993/94, 1997/98, 2001/02, 2005/06, 2009/10, 2013/14, 2017/18
- Greece: 1997/98, 2001/02, 2005/06, 2009/10, 2013/14, 2017/18
- Greenland: 1993/94, 1997/98, 2001/02, 2005/06, 2009/10, 2013/14, 2017/18
- Hungary: 1985/86, 1989/90, 1993/94, 1997/98, 2001/02, 2005/06, 2009/10, 2013/14, 2017/18
- Iceland: 2005/06, 2009/10, 2013/14, 2017/18
- Ireland: 1997/98, 2001/02, 2005/06, 2009/10, 2013/14, 2017/18
- Israel: 1985/86, 1989/90, 1993/94, 1997/98, 2001/02, 2005/06, 2009/10, 2013/14, 2017/18**
- Italy: 2001/02, 2005/06, 2009/10, 2013/14, 2017/18
- Kazakhstan: 2017/18
- Latvia: 1989/90**, 1993/94, 1997/98, 2001/02, 2005/06, 2009/10, 2013/14, 2017/18
- Lithuania: 1993/94, 1997/98, 2001/02, 2005/06, 2009/10, 2013/14, 2017/18
- Luxembourg: 2005/06, 2009/10, 2013/14, 2017/18
- Malta: 2001/02, 2005/06, 2009/10, 2013/14, 2017/18
- Moldova: 2013/14, 2017/18
- Netherlands: 1985/86**, 1989/90**, 2001/02, 2005/06, 2009/10, 2013/14, 2017/18
- North Macedonia: 2001/02, 2005/06, 2009/10, 2013/14, 2017/18
- Northern Ireland: 1989/90**, 1993/94, 1997/98
- Norway: all rounds (1983/84–2017/18)
- Poland: 1989/90, 1993/94, 1997/98, 2001/02, 2005/06, 2009/10, 2013/14, 2017/18
- Portugal: 1997/98, 2001/02, 2005/06, 2009/10, 2013/14, 2017/18
- Romania: 2005/06, 2009/10, 2013/14, 2017/18
- Russian Federation: 1989/90, 1993/94, 1997/98, 2001/02, 2005/06, 2009/10, 2013/14
- Scotland: 1985/86, 1989/90, 1993/94, 1997/98, 2001/02, 2005/06, 2009/10, 2013/14, 2017/18
- Serbia: 2017/18
- Slovakia: 1993/94, 1997/98, 2001/02, 2005/06, 2009/10, 2013/14, 2017/18
- Slovenia: 2001/02, 2005/06, 2009/10, 2013/14, 2017/18
- Spain: 1985/86, 1989/90, 1993/94, 2001/02, 2005/06, 2009/10, 2013/14, 2017/18
- Sweden: 1985/86, 1989/90, 1993/94, 1997/98, 2001/02, 2005/06, 2009/10, 2013/14, 2017/18
- Switzerland: 1985/86, 1989/90, 1993/94, 1997/98, 2001/02, 2005/06, 2009/10, 2013/14, 2017/18
- Turkey: 2005/06, 2009/10, 2017/18**
- USA: 1997/98, 2001/02, 2005/06, 2009/10
- Ukraine: 2001/02, 2005/06, 2009/10, 2013/14, 2017/18
- Wales: 1985/86, 1989/90, 1993/94, 1997/98, 2001/02, 2005/06, 2009/10, 2013/14, 2017/18
* A single national file was submitted. ** The survey was carried out after the scheduled fieldwork dates.