It’s been 15 months since President Obama placed a phone call from the Oval Office in the White House to Havana, Cuba. He was calling Raul Castro. That conversation upturned more than a half century of American foreign policy as relations have moved from silent isolation to a presidential visit. A lot of history has been made in those short 15 months. Here's some of that history by the numbers: 88 • number of years since a sitting U.S. president visited Cuba 3.5 million • number of tourists to