| Año | Valor |
|---|---|
| 1990-01-01 | 3.530900 |
| 1991-01-01 | 3.485200 |
| 1992-01-01 | 4.061400 |
| 1993-01-01 | 4.708900 |
| 1994-01-01 | 6.044100 |
| 1995-01-01 | 5.722100 |
| 1996-01-01 | 7.092000 |
| 1997-01-01 | 8.083400 |
| 1998-01-01 | 7.261500 |
| 1999-01-01 | 7.295700 |
| 2000-01-01 | 6.829300 |
| 2001-01-01 | 7.926500 |
| 2002-01-01 | 7.244900 |
| 2003-01-01 | 5.661800 |
| 2004-01-01 | 4.334400 |
| 2005-01-01 | 2.608400 |
| 2006-01-01 | 9.827700 |
| 2007-01-01 | 4.402900 |
| 2008-01-01 | 4.736500 |
| 2009-01-01 | 5.266100 |
Fuente: World Bank