人民幣NDF買入價賣出價一周6.14456.1455一月6.13806.1400二月6.13806.1410三月6.13656.1395六月6.14406.1470九月6.15106.1550一年6.15806.1630二年6.20156.2065三年6.24356.2485四年6.26156.2665五年6.25856.2635?