| Año | Valor |
|---|---|
| 1961-01-01 | 6.548173 |
| 1962-01-01 | 3.561471 |
| 1963-01-01 | 0.824215 |
| 1964-01-01 | 8.385943 |
| 1965-01-01 | 5.891025 |
| 1966-01-01 | 3.315876 |
| 1967-01-01 | 6.232459 |
| 1968-01-01 | 4.588484 |
| 1969-01-01 | 3.719008 |
| 1970-01-01 | 3.960561 |
| 1971-01-01 | 2.538632 |
| 1972-01-01 | 18.977749 |
| 1973-01-01 | 42.944509 |
| 1974-01-01 | 61.545960 |
| 1975-01-01 | 6.695278 |
| 1976-01-01 | 8.598921 |
| 1977-01-01 | 12.540618 |
| 1978-01-01 | 14.103811 |
| 1979-01-01 | 19.797174 |
| 1980-01-01 | 25.048718 |
Fuente: World Bank