Nearly 15 percent of professionals working as individual businesses made less than 2 million won ($1,765), or one-tenth of an average of income in these traditionally highly paid professions, suggesting growing competition in the professional market.

While those in these professions, a total of 35,108, earned an average of 230.8 million won a year, 14.3 percent of the group made a monthly income of 2 million won or 24 million won a year, according to data provided by the National Tax Service requested by Rep. Park Gwang-on.

Of the group who made less than 2 million won a month, architects accounted for 46.3 percent, followed by lawyers and judicial scrivener with 17.7 percent and 14.9 percent, respectively.

Meanwhile, the top-paid professionals included patent attorneys who earned 600 million won a year, followed by lawyers and accountants who made 412 million won and 325 million won, respectively.