Earnings of the country's No. 1 conglomerate, Samsung Group, took up almost half of the total of the top 10 groups in 2013, the latest reminder of a deepening polarization of corporate performance in South Korea, data showed Wednesday. The combined operating income of 81 listed firms affiliated with the nation's top 10 conglomerates reached 79.77 trillion won (US$75.43 billion) last year, rising 7.5 percent or 5.54 trillion won from 74.23 trillion won a year earlier, according to the data compiled by financial service provider FnGuide Inc.