However, it is expected to rise to a staggering 98% in 2010.

staggering 是形容词，由动词 stagger（蹒跚、摇晃）加上后缀 -ing 构成。原意是"使人站立不稳的"，引申为"令人震惊的、惊人的"，用来形容数量或程度之大让人难以置信。