In a given economy, the Consumer Prices Index (CPI) was recorded at 142.5 in December 2022 and fell to 133.8 in December 2023 due to a contraction in aggregate demand. What was the annual rate of inflation for 2023, to one decimal place, as measured by this CPI?
−6.5%-6.5\%−6.5%
−6.1%-6.1\%−6.1%
−8.7%-8.7\%−8.7%
+6.1%+6.1\%+6.1%