| Año | Valor |
|---|---|
| 1971-01-01 | 8.120591 |
| 1972-01-01 | 8.719773 |
| 1973-01-01 | 11.803818 |
| 1974-01-01 | 26.655573 |
| 1975-01-01 | 18.227823 |
| 1976-01-01 | 15.200619 |
| 1977-01-01 | 17.209779 |
| 1978-01-01 | 14.092519 |
| 1979-01-01 | 20.042684 |
| 1980-01-01 | 19.871577 |
| 1981-01-01 | 12.967566 |
| 1982-01-01 | 16.439331 |
| 1983-01-01 | 12.216723 |
| 1984-01-01 | 12.082403 |
| 1985-01-01 | 10.054581 |
| 1986-01-01 | 9.053072 |
| 1987-01-01 | 8.936103 |
| 1988-01-01 | 9.456342 |
| 1989-01-01 | 13.318361 |
| 1990-01-01 | 11.691853 |
Fuente: World Bank