| Año | Valor |
|---|---|
| 1990-01-01 | 6.581600 |
| 1991-01-01 | 6.897500 |
| 1992-01-01 | 7.429500 |
| 1993-01-01 | 8.887500 |
| 1994-01-01 | 9.592200 |
| 1995-01-01 | 8.671800 |
| 1996-01-01 | 8.383000 |
| 1997-01-01 | 10.164700 |
| 1998-01-01 | 10.171500 |
| 1999-01-01 | 8.873500 |
| 2000-01-01 | 8.200700 |
| 2001-01-01 | 7.931700 |
| 2002-01-01 | 8.463000 |
| 2003-01-01 | 9.013800 |
| 2004-01-01 | 9.445100 |
| 2005-01-01 | 9.929300 |
| 2006-01-01 | 10.773000 |
| 2007-01-01 | 11.986700 |
| 2008-01-01 | 12.833700 |
| 2009-01-01 | 13.648100 |
Fuente: World Bank