| Año | Valor |
|---|---|
| 1970-01-01 | 12.709400 |
| 1971-01-01 | 14.466200 |
| 1972-01-01 | 14.623900 |
| 1973-01-01 | 14.480900 |
| 1974-01-01 | 14.502900 |
| 1975-01-01 | 14.460700 |
| 1976-01-01 | 14.644000 |
| 1977-01-01 | 15.817600 |
| 1978-01-01 | 16.276600 |
| 1979-01-01 | 20.267900 |
| 1980-01-01 | 10.863100 |
| 1981-01-01 | 9.147800 |
| 1982-01-01 | 6.907600 |
| 1983-01-01 | 7.475500 |
| 1984-01-01 | 11.535800 |
| 1985-01-01 | 13.393800 |
| 1986-01-01 | 13.355800 |
| 1987-01-01 | 13.973300 |
| 1988-01-01 | 7.055700 |
| 1989-01-01 | 6.026600 |
Fuente: World Bank