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
| Datum | Wert | Ändern , % |
|---|---|---|
| 2021 | 51 | 15,34 % |
| 2020 | 45 | -0,66 % |
| 2019 | 45 | 13,39 % |
| 2018 | 40 | 6,75 % |
| 2017 | 37 | -2,07 % |
| 2016 | 38 | 18,62 % |
| 2015 | 32 | 2,23 % |
| 2014 | 31 | 9,51 % |
| 2013 | 28 | 11,18 % |
| 2012 | 26 | 2,57 % |
| 2011 | 25 | 10,39 % |
| 2010 | 23 |