| Rank | Country | Value | Year |
|---|---|---|---|
| 1 | Estonia | 4.23 | 2019 |
| 2 | Lithuania | 3.84 | 2019 |
| 3 | Sweden | 3.7 | 2019 |
| 4 | Poland | 3.43 | 2019 |
| 5 | United Kingdom | 3.41 | 2019 |
| 6 | Denmark | 3.4 | 2019 |
| 7 | Slovenia | 3.26 | 2019 |
| 8 | Slovak Republic | 3.02 | 2019 |
| 9 | Latvia | 2.75 | 2019 |
| 10 | Croatia | 2.55 | 2019 |
| 11 | Taiwan, China | 2.55 | 2019 |
| 12 | Germany | 2.26 | 2019 |
| 13 | Austria | 2.25 | 2019 |
| 14 | United States | 2.21 | 2019 |
| 15 | Czech Republic | 2.17 | 2019 |
| 16 | Norway | 2.15 | 2019 |
| 17 | France | 2.13 | 2019 |
| 18 | Switzerland | 2.06 | 2019 |
| 19 | Bulgaria | 2.05 | 2019 |
| 20 | Australia | 1.97 | 2019 |
| 21 | Finland | 1.89 | 2019 |
| 22 | Portugal | 1.89 | 2019 |
| 23 | Hungary | 1.87 | 2019 |
| 24 | China | 1.71 | 2019 |
| 25 | Italy | 1.65 | 2019 |
| 26 | Chile | 1.57 | 2019 |
| 27 | Canada | 1.54 | 2019 |
| 28 | Belgium | 1.5 | 2019 |
| 29 | Japan | 1.45 | 2019 |
| 30 | Russian Federation | 1.45 | 2019 |
| 31 | Serbia | 1.23 | 2019 |
| 32 | Morocco | 1.1 | 2019 |
| 33 | South Africa | 1.08 | 2019 |
| 34 | Netherlands | 1.02 | 2019 |
| 35 | Colombia | 1.01 | 2019 |
| 36 | Spain | 0.82 | 2019 |
| 37 | Mexico | 0.76 | 2019 |
| 38 | Korea, Rep. | 0.73 | 2019 |
| 39 | Peru | 0.71 | 2019 |
| 40 | Kenya | 0.53 | 2019 |
| 41 | Ukraine | 0.47 | 2019 |
| 42 | Turkey | 0.42 | 2019 |
| 43 | Malaysia | 0.36 | 2019 |
| 44 | Egypt, Arab Rep. | 0.29 | 2019 |
| 45 | Greece | 0.25 | 2019 |
| 46 | Brazil | 0.23 | 2019 |
| 47 | Nigeria | 0.23 | 2019 |
| 48 | Iran, Islamic Rep. | 0.13 | 2019 |
| 49 | India | 0.05 | 2019 |