The chart doesn't specify what their data sources are. There are a number of conflicting agendas that go into the reporting of illegal markets. The police want

The chart doesn't specify what their data sources are. There are a number of conflicting agendas that go into the reporting of illegal markets. The police want to make the criminals appear wealthier, to justify more police enforcement, so they tend to inflate statistics. Caught criminals want to be able to hide some of their cash so they tend to deflate their prices. Some of these differences likely reflect the reporting methods, and not the underlying markets.