The BLS releases data on occupational level employment here: http://www.bls.gov/oes/tables.htm. Each section is labeled with a year (such as "May 2015").
What year does the May 2015 data represent? Is it employment in 2014?
Now from the FAQ:
When will this year's OES estimates be available? Estimates are generally released in late March or early April. Please check the OES homepage around that time for a scheduled release date.
The also use the PAST 3 years of data to produce the May 2015 estimates.
Significant reductions in sampling error can be achieved by taking advantage of a full three years of data, covering 1.2 million establishments and about 57 percent of the employment in the United States. This feature is particularly important in improving the reliability of estimates for detailed occupations in small geographical areas. The May 2015 employment and wage estimates were calculated using data collected in the May 2015, November 2014, May 2014, November 2013, May 2013, and November 2012 semi-annual panels.