| Año | Valor |
|---|---|
| 1990-01-01 | 2.753618 |
| 1991-01-01 | 1.373662 |
| 1992-01-01 | 1.420973 |
| 1993-01-01 | 1.393740 |
| 1994-01-01 | 1.320638 |
| 1995-01-01 | 1.675391 |
| 1996-01-01 | 2.082666 |
| 1997-01-01 | 1.645571 |
| 1998-01-01 | 1.240333 |
| 1999-01-01 | 1.831481 |
| 2000-01-01 | 3.200719 |
| 2001-01-01 | 2.701915 |
| 2002-01-01 | 3.201434 |
| 2003-01-01 | 3.578410 |
| 2004-01-01 | 5.088681 |
| 2005-01-01 | 7.330803 |
| 2006-01-01 | 6.905111 |
| 2007-01-01 | 4.874828 |
| 2008-01-01 | 5.133589 |
| 2009-01-01 | 1.999019 |
Fuente: World Bank