Here's an updated calculation. I used the statistical data on the Ebola 2014 Wiki page to refactor the death rate and rate of infection based on actual statistical data.
Average Death Rate: 0.611
Average Rate of Infection: 1.928
Mar, 2014 - Infected: 106 Dead: 65 ROI: 1.92
Apr, 2014 - Infected: 203 Dead: 124 ROI: 1.92
May, 2014 - Infected: 389 Dead: 238 ROI: 1.92
Jun, 2014 - Infected: 747 Dead: 457 ROI: 1.92
Jul, 2014 - Infected: 1,435 Dead: 877 ROI: 1.92
Aug, 2014 - Infected: 2,755 Dead: 1,684 ROI: 1.92
Sep, 2014 - Infected: 5,290 Dead: 3,234 ROI: 1.92
Oct, 2014 - Infected: 10,157 Dead: 6,209 ROI: 1.92
Nov, 2014 - Infected: 19,502 Dead: 11,921 ROI: 1.92
Dec, 2014 - Infected: 37,443 Dead: 22,889 ROI: 1.92
Jan, 2015 - Infected: 71,891 Dead: 43,947 ROI: 1.92
Feb, 2015 - Infected: 138,031 Dead: 84,379 ROI: 1.92
Mar, 2015 - Infected: 265,020 Dead: 162,007 ROI: 1.92
Apr, 2015 - Infected: 508,838 Dead: 311,053 ROI: 1.92
May, 2015 - Infected: 976,970 Dead: 597,222 ROI: 1.92
Jun, 2015 - Infected: 1,875,782 Dead: 1,146,665 ROI: 1.92
Jul, 2015 - Infected: 3,601,501 Dead: 2,201,598 ROI: 1.92
Aug, 2015 - Infected: 6,914,883 Dead: 4,227,068 ROI: 1.92
Sep, 2015 - Infected: 13,276,574 Dead: 8,115,970 ROI: 1.92
Oct, 2015 - Infected: 25,491,023 Dead: 15,582,662 ROI: 1.92
Nov, 2015 - Infected: 48,942,764 Dead: 29,918,712 ROI: 1.92
Dec, 2015 - Infected: 93,970,107 Dead: 57,443,926 ROI: 1.92
Jan, 2016 - Infected: 180,422,605 Dead: 110,292,339 ROI: 1.92
Feb, 2016 - Infected: 346,411,402 Dead: 211,761,290 ROI: 1.92
Mar, 2016 - Infected: 665,109,892 Dead: 406,581,677 ROI: 1.92
Apr, 2016 - Infected: 1,277,010,993 Dead: 780,636,820 ROI: 1.92
May, 2016 - Infected: 2,451,861,106 Dead: 1,498,822,694 ROI: 1.92
Jun, 2016 - Infected: 4,707,573,324 Dead: 2,877,739,573 ROI: 1.92
Data from Wiki used to recalculate the numbers.
[link to en.wikipedia.org]