| Año | Valor |
|---|---|
| 1986-01-01 | 24.270033 |
| 1987-01-01 | 17.965229 |
| 1988-01-01 | 21.640254 |
| 1989-01-01 | 24.005065 |
| 1990-01-01 | 31.382032 |
| 1991-01-01 | 32.051374 |
| 1992-01-01 | 32.161610 |
| 1993-01-01 | 29.642262 |
| 1994-01-01 | 27.559445 |
| 1995-01-01 | 27.483444 |
| 1996-01-01 | 22.967888 |
| 1997-01-01 | 15.289297 |
| 1998-01-01 | 17.109705 |
| 1999-01-01 | 16.414827 |
| 2000-01-01 | 16.427126 |
| 2001-01-01 | 17.805653 |
| 2002-01-01 | 16.231162 |
| 2003-01-01 | 16.777594 |
| 2004-01-01 | 16.838822 |
| 2005-01-01 | 13.822447 |
Fuente: World Bank