| Año | Valor |
|---|---|
| 1990-01-01 | 0.010900 |
| 1991-01-01 | 0.012400 |
| 1992-01-01 | 0.011900 |
| 1993-01-01 | 0.013500 |
| 1994-01-01 | 0.015500 |
| 1995-01-01 | 0.017800 |
| 1996-01-01 | 0.016000 |
| 1997-01-01 | 0.016800 |
| 1998-01-01 | 0.017600 |
| 1999-01-01 | 0.018500 |
| 2000-01-01 | 0.029700 |
| 2001-01-01 | 0.030600 |
| 2002-01-01 | 0.032100 |
| 2003-01-01 | 0.032900 |
| 2004-01-01 | 0.034500 |
| 2005-01-01 | 0.035800 |
| 2006-01-01 | 0.037900 |
| 2007-01-01 | 0.040100 |
| 2008-01-01 | 0.041200 |
| 2009-01-01 | 0.042800 |
Fuente: World Bank