Figures in constant (2020) US$ are present according to calendar year, calculated on the assumption that, where financial years do not correspond to calendar years, spending is distributed evenly through the year
| التاريخ | Value | تغيير , % |
|---|---|---|
| 2021 | 17,575 | 11.06 % |
| 2020 | 15,825 | -3.01 % |
| 2019 | 16,317 | -17.89 % |
| 2018 | 19,871 | -15.40 % |
| 2017 | 23,488 | 12.51 % |
| 2016 | 20,875 | 14.80 % |
| 2015 | 18,184 | 6.33 % |
| 2014 | 17,102 | -0.29 % |
| 2013 | 17,152 | -19.47 % |
| 2012 | 21,299 | 4.11 % |
| 2011 | 20,458 | -13.69 % |
| 2010 | 23,703 |