Since 2006, $9 billion has been invested in downtown and surrounding neighborhoods; $5.2 billion of that in has come in 2013 and 2014. Construction activity, particularly rehabilitation of historic downtown buildings, has increased markedly. The number of vacant downtown buildings has dropped from nearly 50 to around 13.[when?] Among the most notable redevelopment projects are the Book Cadillac Hotel and the Fort Shelby Hotel; the David Broderick Tower; and the David Whitney Building. Meanwhile, work is underway or set to begin on the historic, vacant Wurlitzer Building and Strathmore Hotel.[citation needed] COUNT 4
QSN1 How much has been invested in Detroit since 2006? ANS1 $9 billion QSN2 Which hotel is set to be renovated? ANS2 Strathmore QSN3 How much money has been invested in Detroit in 2013-2014? ANS3 $5.2 billion QSN4 How many vacant downtown buildings are there in Detroit? ANS4 13