View of US dollar banknotes, in Caracas on March 24, 2014. The Venezuelan government postponed another week the entry into force of the new exchange market announced more than a month ago to control the "black dollar", in a context of inflation and shortages, leading causes of the protests against President Nicolas Maduro which have so far caused 31 deaths.  AFP PHOTO/JUAN BARRETO        (Photo credit should read JUAN BARRETO/AFP via Getty Images)