| Characteristic | 2011 | 2012 | 2013 | 2014 | 2015 | 2016 | 2017 |
|---|---|---|---|---|---|---|---|
| - | - | - | - | - | - | - | - |
| - | - | - | - | - | - | - | - |
| - | - | - | - | - | - | - | - |
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Release date
February 2018
Region
Worldwide
Survey time period
2011 to 2017
Supplementary notes
All figures from 2011-2014 have been taken from earlier reports.
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