Table 2.
Number of studies per country of included articles.
| Country or Countries | Number of studies |
|---|---|
| United States | 21 |
| China | 13 |
| India | 10 |
| Brazil | 9 |
| Netherlands | 4 |
| Egypt | 5 |
| Australia and New Zealand | 3 |
| Bangladesh | 3 |
| Spain | 3 |
| Turkey | 3 |
| Austria | 2 |
| Colombia | 2 |
| Pakistan | 2 |
| South Korea | 2 |
| United Kingdom | 2 |
| Argentina, Belgium, Canada, Chile, France, Ghana, Indonesia, Iran, Ireland, Japan, Poland, Saudi Arabia, Tanzania, Uganda | 1 each |
| United Kingdom and United States | 1 |
| Austria, Germany, Lithuania, Netherlands, Spain, Switzerland, United Kingdom | 1 |