Salary data 

BLR Salary Finder data is updated twice annually, in March and in September. It includes employment and wage estimates for over 800 occupational job families, including the number of jobs in certain occupations, and estimates of the wages paid to them. These estimates are available for the nation as a whole, for individual States, and for metropolitan statistical areas (MSAs), metropolitan divisions, and non-metropolitan areas.

The data includes both industry-specific and cross-industry estimates. Industry-specific estimates are calculated with data collected from establishments in one particular industry. Since different industries employ people in different occupations, the occupations in the staffing pattern for a particular industry will not be the same as the occupations in the staffing pattern for another industry. Cross-industry estimates are calculated with data collected from establishments in all the industries for which a particular occupation is reported. Not every occupation is reported in every industry.

The data represents over 580 metropolitan and non-metropolitan areas, including metropolitan statistical areas (MSAs) and metropolitan divisions. Please note, however, that not all areas have information for all occupations.

The data represents wages and salaries only, and does not include non-production bonuses or employer costs of non-wage benefits, such as health insurance or employer contributions to retirement plans. Wages are straight-time, gross pay, exclusive of premium pay. 

The sum of the metropolitan areas may differ from statewide employment due to rounding or the totals include data items that are not released separately due to confidentiality and quality reasons. Also, many states include metropolitan areas that cross state lines. These cross-state metropolitan area estimates include data from each State, which should not be included in a total for a single state. A small number of establishments indicate the state in which their employees are located, but do not indicate the specific metropolitan or non-metropolitan area in which they are located. Data for these establishments are used in the calculation of the statewide estimates, but are not included in the estimates of any individual area.

If there is no data for a percentile or if n/a is in its place, it means that there is no data available to us or that the data that is available is unreliable. (The data is so out of line with the rest of the data we couldn't use it because it would skew the "mean" to an unrealistic level.) For example, there may not be enough incumbents for that percentile or the calculated number skewed too close to the next percentile. BLS runs algorithms that detect the validity of the data. If the "validity factor" goes above a predetermined level they don't report the number.

Source

Occupational Employment and Wage Statistics (OEWS) program—the only comprehensive source of regularly produced occupational employment and wage rate information for the U.S. economy, as well as States, the District of Columbia, and all metropolitan and non-metropolitan areas in each state.

The OEWS survey is a semi-annual mail survey of non-farm establishments. The sampling frame (the list from which establishments to be surveyed are selected) is derived from the list of establishments maintained by State Workforce Agencies (SWAs) for unemployment insurance purposes. 

OEWS wage data are used to determine salary ranges for different occupations in different locations and in different industries. Additionally, OEWS data are used to establish the fixed employment weights for the Employment Cost Index and in the calculation of occupational rates for the Survey of Occupational Injuries and Illnesses. OEWS wage data are used by academic and government researchers to study labor markets, wage and employment trends, and is frequently cited as the most popular labor market information program within States.

The OEWS program reduces sampling error by taking advantage of a full three years of data, covering 1.1 million establishments in the United States. This feature is particularly important in improving the reliability of estimates for detailed occupations in small geographical areas. Combining multiple years of data is also necessary to obtain full coverage of the largest establishments.

Job titles

The BLR Salary Finder includes employment and wage estimates for over 2,400 job titles. Job titles vary from organization to organization, with an accountant in one organization titled as accounting supervisor in another. Both may have similar duties and responsibilities, though, as well as skills and attributes so can be grouped into a single job family.