In just 16 years at 2.6% CPI, money will lose 50% of its purchasing power. Everyone should protect their savings against inflation.
With continuous compounding, 1/2 = (1-2.6%)^n = 0.974^n n = log(1/2) / log(0.974) = 26.3 y
Same answer on a Deci-Lon.
With annual compounding, HP-12c gives 27y