Amazon may have sold close to 5 million Kindle Fire tablet since the device debuted late last year. At least, that’s the number estimated by Asymco analyst Horace Dediu based on Amazon’s own claims. The retail company said yesterday that the Fire accounted for 22 percent of all tablet sales in the United States over the past nine months. Assuming that number is accurate, here’s how Dediu arrived at total sales of 5 million. Based on testimony from Apple and Samsung at their recent patent trial, the iPad racked up unit sales of 16.14 million from the fourth quarter of 2011 to the second quarter of 2012. Read the full story at CNET.