After a record-low unemployment rate in April, the percentage of unemployed post-9/11 veterans ticked up again in May. 

According to the latest data from the U.S. Bureau of Labor Statistics, 4.6 percent of post-9/11 veterans were unemployed last month, compared to 3.9 percent in April — the lowest on record. Meanwhile, 4 percent of nonveterans were unemployed in May. 

Veterans overall fared better in May than in April. The unemployment rate for all veterans dropped slightly to 3.4 percent, on par with last year's May figure. 

Critics of the federal data warn the numbers are too volatile to put much stock in. The unemployment rate is calculated from a Current Population Survey, which pulls veteran unemployment figures from a much smaller sample size than the overall rate.

The national unemployment rate was 4.3 percent in May. The U.S. added approximately 138,000 more jobs, primarily in the healthcare industry.