Year	current US$
2003	0.3309446940846499
2004	0.4230345779383653
2005	0.4143607500842348
2006	0.32254497016185774
2007	0.332813768165382
2008	0.4016664681089423
2019	0.654423469478724
2020	0.5875464935584476
2021	1.2257609643516678