Given the task definition and input, reply with output. This task is about reading the given passage and construct a question about the information present in the passage. Construct a question in such a way that (i) it is unambiguous, (ii) it is answerable from the passage, (iii) its answer is unique (iv) its answer is a continuous text span from the paragraph. Avoid creating questions that (i) can be answered correctly without actually understanding the paragraph and (ii) uses same words or phrases given in the passage.

Since 2001, Miami has been undergoing a large building boom with more than 50 skyscrapers rising over 400 feet (122 m) built or currently under construction in the city. Miami's skyline is ranked third-most impressive in the U.S., behind New York City and Chicago, and 19th in the world according to the Almanac of Architecture and Design. The city currently has the eight tallest (as well as thirteen of the fourteen tallest) skyscrapers in the state of Florida, with the tallest being the 789-foot (240 m) Four Seasons Hotel & Tower.
How many 400+ foot skyscrapers have been built or are in the process of being built in Miami since 2001?