| Año | Valor |
|---|---|
| 1970-01-01 | 17.163807 |
| 1971-01-01 | 21.690771 |
| 1972-01-01 | 19.149084 |
| 1973-01-01 | 19.228876 |
| 1974-01-01 | 15.501888 |
| 1975-01-01 | 12.631869 |
| 1976-01-01 | 13.503697 |
| 1977-01-01 | 10.300414 |
| 1978-01-01 | 6.157733 |
| 1979-01-01 | 9.604536 |
| 1980-01-01 | 11.239340 |
| 1981-01-01 | 14.451809 |
| 1982-01-01 | 17.157820 |
| 1983-01-01 | 17.367429 |
| 1984-01-01 | 26.856786 |
| 1985-01-01 | 44.868491 |
| 1986-01-01 | 73.780586 |
| 1987-01-01 | 69.335720 |
| 1988-01-01 | 46.977530 |
| 1989-01-01 | 72.489297 |
Fuente: World Bank