5月16日电，房地美数据显示，美国上周30年期按揭贷款/抵押贷款利率6.81%，前值6.76%。

Group 1 - The core point of the article indicates that the 30-year mortgage rate in the United States has increased to 6.81%, up from the previous value of 6.76% [1] Group 2 - The data is sourced from Freddie Mac, which provides insights into the mortgage market trends [1] - The increase in mortgage rates may impact housing affordability and demand in the real estate market [1]