| Año | Valor |
|---|---|
| 1990-01-01 | 49.730402 |
| 1991-01-01 | 41.124780 |
| 1992-01-01 | 45.854063 |
| 1993-01-01 | 41.720106 |
| 1994-01-01 | 51.841360 |
| 1995-01-01 | 56.674395 |
| 1996-01-01 | 54.539839 |
| 1997-01-01 | 53.542627 |
| 1998-01-01 | 56.711590 |
| 1999-01-01 | 52.641072 |
| 2000-01-01 | 48.479381 |
| 2001-01-01 | 45.164532 |
| 2002-01-01 | 46.069295 |
| 2003-01-01 | 53.069671 |
| 2004-01-01 | 51.431718 |
| 2005-01-01 | 58.884592 |
| 2006-01-01 | 56.157832 |
| 2007-01-01 | 56.558430 |
| 2008-01-01 | 60.037018 |
| 2009-01-01 | 61.855836 |
Fuente: World Bank