Here you can see very clearly the development of Chavismo plotted against yearly OPEC oil prices. In red at the end you can see the current (week) average price of OPEC oil.
For those who don't know much about Venezuela: 90% of its foreign income derives from oil exports controlled by the state (it has always been like that). Around 50% of the national tax revenues comes directly from oil and a lot of the taxes that make up the rest are produced by commercial activities largely supported by the oil income itself (like taxes on whiskey or imported cars)
UPDATE: some Chavista supporters came up to tell me the chart proofs Chávez wins most of the elections when prices are low. This shows again their understanding of charts. Apart from Chávez's first elections, when he was new, when he was "the new promise", all other elections he has won have been with prices higher than before. The moment of great distress for him, when he was outsted, was at a time when prices seemed to drop a bit. Of course, now Venezuela has been able to save some money, but it is much less than what Chavismo needs. When Chávez allowed, under international pressure, to have a referendum (one year after it was asked), the government was for a couple of months already giving away for free red bags full of food and a big "NO" (not to the referendum) on them. In 2004 oil prices (and thus, governmental revenues) were much higher than at any given time for many years. But of course, for Chavismo now prices are low if they are not over $100 per barrel...so corrupt has Venezuela become.