Russia’s makes up 39.37 percent of the country’s annual GDP — 33.6 trillion rubles — according to a new study by the Association of Chartered Certified Accountants.

In terms of percentages, that’s the fourth largest shadow economy in the world, behind only Azerbaijan (67 percent), Nigeria (48 percent), and Ukraine (46 percent). ACCA observed the smallest shadow economies in the United States (7.8 percent), Japan (10 percent), and China (10.2 percent).

ACCA’s 28-nation study relies on qualitative interviews with local entrepreneurs and area experts, as well as quantitative mathematical models. Though ACCA expects the global shadow economy to decline by two percentage points by 2025, the association's researchers don't expect the situation to change in Russia.

In April 2017, Russia’s Finance Ministry estimated that Russians received roughly 11 trillion rubles ($186 billion) in “off-the-books,” “under-the-table” income. In 2016, an unnamed federal official told the news agency RIA Novosti that Moscow believes Russia’s shadow economy accounts for only 22 percent of the country’s GDP.