| Año | Valor |
|---|---|
| 1970-01-01 | 1.995459 |
| 1971-01-01 | 1.605686 |
| 1972-01-01 | 1.607741 |
| 1973-01-01 | 4.627837 |
| 1974-01-01 | 8.579186 |
| 1975-01-01 | 4.715689 |
| 1976-01-01 | 4.289771 |
| 1977-01-01 | 4.933493 |
| 1978-01-01 | 5.293842 |
| 1979-01-01 | 8.810239 |
| 1980-01-01 | 11.697120 |
| 1981-01-01 | 5.135768 |
| 1982-01-01 | 3.881839 |
| 1983-01-01 | 4.698110 |
| 1984-01-01 | 3.905239 |
| 1985-01-01 | 3.512395 |
| 1986-01-01 | 2.503856 |
| 1987-01-01 | 3.616385 |
| 1988-01-01 | 5.360422 |
| 1989-01-01 | 7.423795 |
Fuente: World Bank