Source: The Distribution of US Wealth, Capital Income and Returns since 1913
Emmanuel Saez (UC Berkeley)
Gabriel Zucman (LSE and UC Berkeley)
786.000 rich people live in Poland in 2013.
To be one of them you have to earn 85.000 zloty (PLN), i.e. 28.000 USD.
Additionally, 45.000 belongs to HNWI category (High Net Worth Individuals).
This group includes people who have liquid assets (cash, stocks, etc.) with a value in excess of $1 million.
One of the examples:
An Illustrated Guide to Income in the United States
Presentation @ TBP Conference 10.11.11
“Signal and Noise” http://www.amazon.com/The-Signal-Noise-Many-Predictions/dp/159420411X