South Korea’s income disparity significantly widened over the past years with the gap between top and low income earners growing at one of the fastest rates in the world, data showed Sunday.

According to the state statistics office, the average monthly income of South Korea’s urban households nearly doubled from about 2.1 million won ($2,000) in 1990 to a little over 3.9 million won last year.

However, the country’s Gini coefficient widened from 0.256 to 0.280 over the cited period.

Gini coefficient is one of the main measures that gauge income disparity between the haves and have-nots. A reading of zero means complete income equality, while higher numbers nearing 1 indicate a widening gap in earnings between the rich and poor.

The Gini index for the country’s overall households came to 0.302 in 2013. A recent report from the Asian Development Bank showed that South Korea’s Gini index grew at the fifth fastest rate among 28 Asian countries surveyed between 1990 and 2010 after those of China, Indonesia, Laos and Sri Lanka. (Yonhap)