In a given economy, the Consumer Prices Index (CPI) was 136.4 in 2022 and 142.8 in 2023. What was the annual rate of inflation for 2023, to one decimal place, as measured by this CPI?
+4.5%+4.5\%+4.5%
+6.4%+6.4\%+6.4%
+4.7%+4.7\%+4.7%
−4.7%-4.7\%−4.7%