Complex sentence: South Korea is by far the most highly developed country when compared to the BRICs and Next 11, yet it has been achieving growth rates of 4-6%, a figure more than double that of other advanced economies.
Split into simpler sentences: South Korea is by far the most highly developed country when compared to the BRICs and N-11s. Yet, it has been achieving growth rates of 4-6%, a figure more than double that of other advanced economies.