Suppose on January 15, 2018, the U.S. Treasury issued a five-year inflation-indexed note with a coupon of 4%. On the date of issue, the consumer price index (CPI) was 260. By January 15, 2023, the CPI had increased to 324. What principal and coupon payment was made on January 15, 2023? (Note: U.S. Treasury pays semi-annual coupons)

The CPI index appreciated by ___ (Round to five decimal places.)