Few thoughts about this interesting analysis.

Forget Virat Kohli, as per your data, even MS Dhoni is a better batsman that Sachin! And Rohit Sharma is as good. Which suggests that, either the reduction factor of 0.42 which you are using per year is not representative of the actual improvement in batting averages per year. Or, batting averages (as you too have accepted) are not the right metric to measure performances across generations. Needless to say, Sachin fan here ;)