(Adds byline, quote, table) By Trevor Hunnicutt NEW YORK, Nov 29 (Reuters) - U.S. mutual fund investors pulled $13.7 billion from stocks and bonds during the latest week, according to data released on Thursday by Lipper underscoring retail investors' rising concerns over turbulent markets. After a sprinting start to 2018 that saw markets rally, the following months have brought concerns over tariffs, rising U.S. interest rates and slowing economic growth. The combination has led, unusually, to mediocre returns across several types of financial assets, including both stocks and bonds. The average U.S.-based stock fund is down 2.6 percent this year while the typical bond fund has fallen 1.3 percent, according to Refinitiv's Lipper research service. "We had a flop in oil and I think it had people concerned about the global growth issue," said Tom Roseen, head of research services for Lipper. "People were still waiting to see what is going to happen." Benchmark U.S. crude oil futures fell further during the week from their highs this year approaching $80, and on Thursday were down around $51. Meanwhile, trade tariffs continue to be at the top of investors' worry list ahead of U.S. President Donald Trump's meeting with Chinese President Xi Jinping on Saturday. Exchange-traded funds (ETFs) showed positive sales across stocks and bonds during the week, according to Lipper's data for the seven days through Nov. 28. The following is a breakdown of the flows for the week, including mutual funds and ETFs: Sector Flow Chg % Assets Assets Count ($blns) ($blns) All Equity Funds -8.467 -0.12 7,065.501 12,145 -Domestic Equities -6.701 -0.14 5,054.770 8,629 -Non-Domestic Equities -1.765 -0.09 2,010.731 3,516 All Taxable Bond Funds -2.443 -0.09 2,761.493 6,002 All Money Market Funds 4.976 0.18 2,813.585 1,016 All Municipal Bond Funds -0.379 -0.09 421.816 1,437 (Reporting by Trevor Hunnicutt Editing by James Dalgleish and Tom Brown)