| Año | Valor |
|---|---|
| 1990-01-01 | 3.041738 |
| 1991-01-01 | 1.187888 |
| 1992-01-01 | 1.097270 |
| 1993-01-01 | 0.798346 |
| 1994-01-01 | 1.738909 |
| 1995-01-01 | 2.043891 |
| 1996-01-01 | 1.462128 |
| 1997-01-01 | 1.269537 |
| 1998-01-01 | 0.169697 |
| 1999-01-01 | 0.211121 |
| 2000-01-01 | 0.278148 |
| 2001-01-01 | 0.121157 |
| 2002-01-01 | 0.224690 |
| 2003-01-01 | 0.234738 |
| 2004-01-01 | 0.563598 |
| 2005-01-01 | 0.913753 |
| 2006-01-01 | 3.576706 |
| 2007-01-01 | 4.520674 |
| 2008-01-01 | 3.462526 |
| 2009-01-01 | 1.631662 |
Fuente: World Bank