Shadow economy - Country rankings:
The average for 2015 was 27.81 percent.The highest value was in Zimbabwe: 67 percent and the lowest value was in Switzerland: 6.94 percent. Below is a chart for all countries where data are available for: Shadow economy.
Shadow economy, percent of GDP, 2015
(percent, Source: Medina and Schneider (2018), TheGlobalEconomy.com)