| Año | Valor |
|---|---|
| 1970-01-01 | 0.297700 |
| 1971-01-01 | 0.310100 |
| 1972-01-01 | 0.321800 |
| 1973-01-01 | 0.334500 |
| 1974-01-01 | 0.341600 |
| 1975-01-01 | 0.353500 |
| 1976-01-01 | 0.366100 |
| 1977-01-01 | 0.378300 |
| 1978-01-01 | 0.389900 |
| 1979-01-01 | 0.402400 |
| 1980-01-01 | 0.414700 |
| 1981-01-01 | 0.422500 |
| 1982-01-01 | 0.428500 |
| 1983-01-01 | 0.435600 |
| 1984-01-01 | 0.443400 |
| 1985-01-01 | 0.457600 |
| 1986-01-01 | 0.461100 |
| 1987-01-01 | 0.464300 |
| 1988-01-01 | 0.471100 |
| 1989-01-01 | 0.476600 |
Fuente: World Bank