The source is mongobay.com.

"A growing acknowledgment of the unsustainable pace of public and private expansion became the focus of the 1978-79 electoral campaign. Because of renewed surges in the price of oil from 1978 to 1982, however, the government of Luis Herrera Campins (president, 1979-84) scrapped plans to downgrade government activities, and the spiral of government spending resumed. In 1983, however, the price of oil fell and soaring interest rates caused the national debt to multiply. Oil revenues could no longer support the array of government subsidies, price controls, exchange-rate losses, and the operations of more than 400 public institutions. Widespread corruption and political patronage only exacerbated the situation.

The government of Jaime Lusinchi (president, 1984-89) attempted to reverse the 1983 economic crisis through devaluations of the currency, a multi-tier exchange-rate system, greater import protection, increased attention to agriculture and food self-sufficiency, and generous use of producer and consumer subsidies. These 1983 reforms stimulated a recovery from the negative growth rates of 1980-81 and the stagnation of 1982 with sustained modest growth from 1985 to 1988. By 1989, however, the economy could no longer support the high rates of subsidies and the increasing foreign debt burden, particularly in light of the nearly 50 percent reduction of the price of oil during 1986"

The above copy-paste is about Vz.

Isn't it interesting how history repeats itself.

From 1930 to 1970 Vz had a reasonable increase of GDP of 3%,

After that inflation skyrocketed.