有段句子想請教
By 2006 , this summer had increased to 113,000 , which is estimated to
have added US 1.3 billion to Australia's economy in that year .
請問為何estimated to +have + pp ?
我的理由是上下句是同一時間(指2006年),所以時式應該一樣
所以應該是estimated to add....而不是estimated to have added...
請問各位有何見解能替小弟解惑
謝謝

不是summer 而是number

時態是一樣啊 都是完成式(直到2006這時間點)

如果時間點一樣為何是"which 'is' estimated"？所以相較於現在，add的動作更先發生，因此用"to have added"