During a certain six-year period the consumer price index increased by 50 but during the next six year period it increased by only 30 What is this called?

This situation is an example of inflation, where the consumer price index (CPI) measures the average change in prices over time. The first six-year period experienced a higher rate of inflation (50), while the second period saw a lower rate (30). This fluctuation in the rate of inflation reflects changes in economic conditions, such as supply and demand, monetary policy, and other factors influencing prices.