| Año | Valor |
|---|---|
| 1985-01-01 | 15.455476 |
| 1986-01-01 | 18.712109 |
| 1987-01-01 | 19.093213 |
| 1988-01-01 | 17.007754 |
| 1989-01-01 | 14.579169 |
| 1990-01-01 | 13.002237 |
| 1991-01-01 | 11.141859 |
| 1992-01-01 | 11.974275 |
| 1993-01-01 | 10.504382 |
| 1994-01-01 | 10.860169 |
| 1995-01-01 | 11.161455 |
| 1996-01-01 | 8.189048 |
| 1997-01-01 | 8.980897 |
| 1998-01-01 | 8.776881 |
| 1999-01-01 | 8.290933 |
| 2000-01-01 | 8.116254 |
| 2001-01-01 | 7.338112 |
| 2002-01-01 | 6.533084 |
| 2003-01-01 | 5.667867 |
| 2004-01-01 | 5.052940 |
Fuente: World Bank