There is no exact means of establishing a starting date, and in this case the final year seems to be off by the number of Hebrew Tribes.
The Fibonacci Sequence depicted in the image is 7.8 Billion people in the year 2008 (it would be more accurate with possible adjustments, but there is neither practical, nor purpose, for that level of enhanced accuracy – after all, even the population numbers we use are just estimates).
OMER is a number count 7x7 years with the 50th year as the celebration. The Book of Revelation modified the Davidic Prophecy so that the original loss of half of all life became the loss of a third. If that is true, and the reports from the scientific community would seem to support it, then we can expect the population to peak at 12.6 Billion and then reduce to around the 8.4 Billion mark.
We need not believe in mystical powers to assert there is a scientific and mathematical basis for the calculation. It doesn’t matter if you are religious or a secular humanist – the reality seems to support the idea that the prediction is proving accurate. We need to wonder about the Evangelical types who are not onboard with it – after all, it is what they have said they believe. Why are they acting as if they don’t believe their own book?