Response rates by participating countries
| Country | Responses (2018) | Responses (2014) | Country | Responses (2018) | Responses (2014) |
| Albania | 1 | 0 | Latvia | 4 | 2 |
| Austria | 29 | 21 | Lithuania | 1 | 8 |
| Belgium | 90 | 94 | Luxembourg | 3 | 0 |
| Bosnia & Herzegovina | 19 | 9 | Malta | 6 | 11 |
| Bulgaria | 3 | 6 | Montenegro | 4 | 0 |
| Croatia | 26 | 25 | Netherlands | 20 | 11 |
| Cyprus | 2 | 1 | Norway | 21 | 11 |
| Czech Republic | 26 | 4 | Poland | 32 | 13 |
| Denmark | 10 | 25 | Portugal | 85 | 42 |
| Estonia | 17 | 15 | Romania | 24 | 2 |
| Finland | 33 | 1 | Russia | 1 | 0 |
| France | 192 | 3 | Serbia | 20 | 8 |
| FYROM | 14 | 4 | Slovakia | 23 | 16 |
| Germany | 78 | 10 | Slovenia | 18 | 5 |
| Greece | 84 | 14 | Spain | 190 | 105 |
| Hungary | 33 | 12 | Sweden | 5 | 0 |
| Iceland | 9 | 4 | Switzerland | 67 | 7 |
| Ireland | 51 | 47 | Turkey | 61 | 5 |
| Italy | 73 | 41 | UK | 291 | 7 |