??? ??? ???? 1???? ???? ‘??’?? ??? ??? ????? ???? ???? ??? ????.

?????? 9? ??PCS ??? 648?? ???? ?????? ?? ???? ??? ??? ?? ????? ??? ??? ????? ?? ????.

‘???? ????? ?? ?????? ?? ???? ??’? ??? 67.7%? ?? ???. ‘??? ???? ? ??? ??? ??? ?? ??? ???? ??’? ??? 27.9%??. ‘????’? 4.4%.

‘????? ??’? ?? ??? 20? 65.9%, 30? 69.0%, 40? ?? 73.6% ? ??? ???? ?? ??? ???.

??(67%)?? ??(69.6%)? ? ??????.

? ‘???? ?? ?? ????? ?????? ??? ?? ??????’? ??? 79.9%? ‘??’? ????.

????? ???(87.6%) ??(81.5%) ??(74.3%) ??(71.0%) ?? ????.

〈?????〉inchul@donga.com