After the IMF economic crisis in the late 1990s, health inequality in Korea was researched vigorously along with the continued polarization in our society. maybe say what was polarized for clarity

From 1970 to 2010, the mortality gap between education levels stayed the same or increased.

From 2004 to 2017, the life expectancy gap among quintile income brackets increased and is expected to increase again in  2030.

The life expectancy and healthy life expectancy became lower in rural counties and cities compared to those in urban counties and cities in Korea.

The gap in life expectancy and healthy life expectancy among income levels in cities and counties with low life expectancy healthy life expectancy was wide.

The gap in life expectancy among income levels in the same region is larger than the gap in life expectancy among cities and counties.

As of 2017, in terms of Korea's subjective health level, the size of health inequality among quintile income brackets is larger than that of major developed countries.