| Año | Valor |
|---|---|
| 1990-01-01 | 0.001100 |
| 1991-01-01 | 0.001200 |
| 1992-01-01 | 0.001200 |
| 1993-01-01 | 0.001200 |
| 1994-01-01 | 0.001300 |
| 1995-01-01 | 0.001300 |
| 1996-01-01 | 0.001400 |
| 1997-01-01 | 0.001400 |
| 1998-01-01 | 0.001400 |
| 1999-01-01 | 0.001500 |
| 2000-01-01 | 0.001600 |
| 2001-01-01 | 0.001600 |
| 2002-01-01 | 0.001700 |
| 2003-01-01 | 0.001700 |
| 2004-01-01 | 0.001700 |
| 2005-01-01 | 0.001800 |
| 2006-01-01 | 0.001800 |
| 2007-01-01 | 0.001900 |
| 2008-01-01 | 0.001900 |
| 2009-01-01 | 0.002000 |
Fuente: World Bank