| Año | Valor |
|---|---|
| 1961-01-01 | 14.350000 |
| 1962-01-01 | 14.890000 |
| 1963-01-01 | 16.180000 |
| 1964-01-01 | 16.700000 |
| 1965-01-01 | 17.360000 |
| 1966-01-01 | 18.000000 |
| 1967-01-01 | 18.520000 |
| 1968-01-01 | 20.380000 |
| 1969-01-01 | 20.250000 |
| 1970-01-01 | 21.110000 |
| 1971-01-01 | 22.140000 |
| 1972-01-01 | 23.840000 |
| 1973-01-01 | 26.780000 |
| 1974-01-01 | 27.180000 |
| 1975-01-01 | 28.900000 |
| 1976-01-01 | 29.090000 |
| 1977-01-01 | 27.500000 |
| 1978-01-01 | 27.230000 |
| 1979-01-01 | 26.810000 |
| 1980-01-01 | 28.160000 |
Fuente: World Bank