| Año | Valor |
|---|---|
| 1980-01-01 | 17.089494 |
| 1981-01-01 | 16.665005 |
| 1982-01-01 | 27.085471 |
| 1983-01-01 | 17.139047 |
| 1984-01-01 | 14.295285 |
| 1985-01-01 | 19.041081 |
| 1986-01-01 | 12.825620 |
| 1987-01-01 | 15.398911 |
| 1988-01-01 | 17.138494 |
| 1989-01-01 | 20.711514 |
| 1990-01-01 | 24.025561 |
| 1991-01-01 | 28.660167 |
| 1992-01-01 | 36.304614 |
| 1993-01-01 | 45.498238 |
| 1994-01-01 | 49.936059 |
| 1995-01-01 | 48.201845 |
| 1996-01-01 | 52.737230 |
| 1997-01-01 | 58.275423 |
| 1998-01-01 | 64.051843 |
| 1999-01-01 | 64.449993 |
Fuente: World Bank