The rule of 70 is a shortcut to estimate how many years it will take to double something that compounds at a steadygrowthrate (say money, or demand for natural gas).
High savings (sometimes mandatory), interest rate controls, and high economic growth let Chinese banks enjoy a steady interest rate spread and a larger loan volume.
Slowing cost growth would lower the unemployment rate consistent with steady inflation by approximately one-quarter of a percentage point for a number of years.