| Año | Valor |
|---|---|
| 1990-01-01 | 0.488400 |
| 1991-01-01 | 0.499800 |
| 1992-01-01 | 0.495400 |
| 1993-01-01 | 0.493300 |
| 1994-01-01 | 0.502300 |
| 1995-01-01 | 0.503900 |
| 1996-01-01 | 0.507800 |
| 1997-01-01 | 0.509000 |
| 1998-01-01 | 0.512300 |
| 1999-01-01 | 0.507500 |
| 2000-01-01 | 0.499900 |
| 2001-01-01 | 0.511100 |
| 2002-01-01 | 0.528000 |
| 2003-01-01 | 0.540000 |
| 2004-01-01 | 0.561700 |
| 2005-01-01 | 0.575200 |
| 2006-01-01 | 0.552900 |
| 2007-01-01 | 0.577500 |
| 2008-01-01 | 0.582800 |
| 2009-01-01 | 0.607000 |
Fuente: World Bank