It is difficult to predict for eight years. 60% is a very high number even for a couple of years. Also ICICI Pru Life is not a small company in small/mid cap space.
Value of New Business (VNB): VNB is used to measure profitability of the new business written in a period. It is present value of all future profits to shareholders measured at the time of writing of the new business contract. Future profits are computed on the basis of long term assumptions which are reviewed annually. Also referred to as NBP (new business profit). [From ICICI Pru Life disclosures].
Please take time to go through a couple of annual reports, DRHPs of insurance companies for better understanding. You may also go through this thread for more information: Life Insurance Companies - Comparison.