Question: "Up to 30,000 visitors were expected annually, but all after what event?"  Context: "The UK government has spent £250 million in the construction of the island's airport. Expected to be fully operational early 2016, it is expected to help the island towards self-sufficiency and encourage economic development, reducing dependence on British government aid. The airport is also expected to kick start the tourism industry, with up to 30,000 visitors expected annually. As of August, 2015 ticketing was postponed until an airline could be firmly designated."  Answer:
A:
the construction of the island's airport