BEIJING, March 6 (Xinhua) -- The value of bonds issued in China last year totaled 43.1 trillion yuan (about 6.4 trillion U.S. dollars), up 7.5 percent year on year, according to data from the country's central bank.

The People's Bank of China (PBOC), the central bank, owed the rise to the notable increases in issuances of non-financial enterprise debt financing instruments and interbank negotiable certificates of deposits.

By the end of 2018, China's outstanding bonds amounted to 86 trillion yuan, surging 15.1 percent year on year.

Bond issuance interest rates saw notable declines last year, with that of 10-year treasury bonds issued in December dropping 57 basis points from the same period in the previous year to 3.25 percent.

Meanwhile, the interest rate of 7-year financial bonds issued by the China Development Bank stood at 3.6 percent last year, down 134 basis points year on year.

The central bank also said that treasury bonds with maturities of one, three, five, seven and 10 years all saw lower rates of return last year.