| Año | Valor |
|---|---|
| 1990-01-01 | 50.269598 |
| 1991-01-01 | 58.875220 |
| 1992-01-01 | 54.145937 |
| 1993-01-01 | 58.279894 |
| 1994-01-01 | 48.158640 |
| 1995-01-01 | 43.325605 |
| 1996-01-01 | 45.460161 |
| 1997-01-01 | 46.457373 |
| 1998-01-01 | 43.288410 |
| 1999-01-01 | 47.358928 |
| 2000-01-01 | 49.768814 |
| 2001-01-01 | 54.262748 |
| 2002-01-01 | 53.023895 |
| 2003-01-01 | 46.059554 |
| 2004-01-01 | 48.459471 |
| 2005-01-01 | 41.026257 |
| 2006-01-01 | 43.977282 |
| 2007-01-01 | 43.919648 |
| 2008-01-01 | 40.545011 |
| 2009-01-01 | 38.786001 |
Fuente: World Bank