| Año | Valor |
|---|---|
| 1990-01-01 | 0.637700 |
| 1991-01-01 | 0.664900 |
| 1992-01-01 | 0.713300 |
| 1993-01-01 | 0.666100 |
| 1994-01-01 | 0.722000 |
| 1995-01-01 | 0.779100 |
| 1996-01-01 | 0.836900 |
| 1997-01-01 | 0.960700 |
| 1998-01-01 | 0.978300 |
| 1999-01-01 | 0.982700 |
| 2000-01-01 | 1.599200 |
| 2001-01-01 | 1.613100 |
| 2002-01-01 | 1.637900 |
| 2003-01-01 | 1.691900 |
| 2004-01-01 | 1.809200 |
| 2005-01-01 | 1.843300 |
| 2006-01-01 | 1.946000 |
| 2007-01-01 | 1.977100 |
| 2008-01-01 | 1.928700 |
| 2009-01-01 | 1.936900 |
Fuente: World Bank