Your numbers and analysis are quite good mathematically. By the end of next May, this could be startling.
Going by the WHO numbers - 800,000 open cases on 1 May, or thereabouts.
Or, going by WHO’s estimate - what they believe the fudge factor is necessary to reflect REAL numbers (4X) - on May 1, 2015, there will be 3.2M open cases of Ebola, worldwide.
Conservatively, by Dec 1, 2015, you are looking at 25.6M open cases of Ebola. That’s still only 0.3% of the 7B people on Earth.
However, by end of the school year, that’s 819.2M people with Ebola in 2016. Congratulations Graduates!