| Characteristic | 2014 | 2015 | 2016 | 2017 | 2018 | 2019 |
|---|---|---|---|---|---|---|
| - | - | - | - | - | - | - |
| - | - | - | - | - | - | - |
| - | - | - | - | - | - | - |
| - | - | - | - | - | - | - |
| - | - | - | - | - | - | - |
| - | - | - | - | - | - | - |
| - | - | - | - | - | - | - |
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Source
Release date
September 2021
Region
Worldwide
Survey time period
2014 to 2019
Supplementary notes
Figures prior to 2019 were taken from previous editions.
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