I don’t find this survey very helpful when the term discrimination is not defined.  I have not been picked up by taxi cabs before, is that discrimination?:

One of out of every five foreigners in South Korea suffer discrimination, due mainly to their nationalities, government data showed Wednesday.
The data compiled by Statistics Korea showed that 21.2 percent of 1.3 million foreigners said they were discriminated by South Koreans. 
Among them, 60.9 percent said they were discriminated on the basis their nationality, while 25.7 percent said they faced discrimination on the grounds of their lack of Korean language proficiency.
The data showed 6.6 percent cited appearance and 2.6. percent pointed to occupation as the reasons behind discrimination.
The statistics agency did not provide details on the nationalities of foreigners who they said were discriminated against.

Yonhap