Salary Survey Extra is a series of periodic dispatches that give added insight into the findings of our most recent Salary Survey. These posts contain previously unpublished Salary Survey data.

How much do you know about ITIL? Would you like to know more? Information Technology Infrastructure Library (ITIL) is a compilation of best practices for IT service delivery to organizations and businesses. The job of an ITIL expert is to maximize the efficiency and effectiveness of IT services in meeting organizational needs.

Initially developed in the United Kingdom (since 2011, ITIL has been owned by AXELOS, a joint venture between the U.K. Cabinet Office and business process outsourcing firm Capita), ITIL has gained global recognition in recent years.

ITIL certification is catching on in the United States, as well. ITIL Foundation, the base layer of the AXELOS ITIL certification pyramid, was No. 43 on this year's Salary Survey 75 list, with 59.7 percent of those surveyed checking in from the United States. The balance of ITIL Foundation-certified individuals tracked in the survey come from 26 different countries around the globe: Argentina, Australia, Belgium, Brazil, Canada, China, Colombia, Finland, Germany, Greece, Hungary, India, Italy, Malaysia, Mexico, Netherlands, Nigeria, Pakistan, Philippines, Poland, Russia, Serbia, Singapore, Switzerland, United Arab Emirates, and the United Kingdom.

Among U.S. ITIL Foundation holders, the average annual salary was $117,590, with a median annual salary of $111,420. The average annual salary across all countries outside the United States is $64,330, with a median annual income of $57,500.

The ITIL Foundation certification is heavily male: Women accounted for just 7.3 percent of respondents, meaning that 92.7 percent of those surveyed are men. Certification holders are strongly concentrated in middle age, with more than 70 percent of respondents either between the ages of 35 and 44 (42.7 percent), or between the ages of 45 and 54 (27.6 percent). There's a modest youth movement, with 18.5 percent of respondents between the ages of 25 and 34, while an additional 2.4 percent are between the ages of 19 and 24. The rest (8.8 percent) are 55 or older.

The highest level of education attained by most ITIL foundation holders in the survey is either a master's degree (39.5 percent) or bachelor's degree (37.9 percent). Most who've never darkened the door of a four-year university have either a two-year college degree (8.1 percent) or post-high school technical training (7.3 percent).

A shade more than 95 percent of ITIL Foundation holders from the survey are employed full-time, with 3.2 unemployed, and the rest scattered more or less evenly between retirement and part-time employment. Among those in the workforce, most either fill a standard 40-hour work week (38.7 percent) or work between 41 and 50 hours per week (38.7 percent). A tick more than 11 percent work more than 50 hours per week, while 6.5 percent work between 31 and 30 hours per week.

Those who have jobs are most likely to be found either at the senior specialist level (41.1 percent), or scattered across corporate leadership, which claims a combined 41 percent who are executives (5.6 percent), directors (7.3 percent), senior managers (12.8 percent), or managers (15.3 percent). That leaves 13.1 percent who are specialists, and 4.8 percent who are mere employees.

The body of ITIL Foundation-certified survey respondents features a strong core of IT veterans, with 47.6 percent having worked in a role that directly calls on their certified skills for more than 10 years. The rest of those surveyed are spread fairly evenly across the spectrum of professional experience, with 10.4 percent having plied their trade for between zero years (1-11 months) and two years, 16.9 percent in the game for between 3 and 5 years, 13.7 percent in the trenches for between 6 and 8 years, and 11.4 percent clocking in for between 9 and 10 years.

Finally, here's the view of ITIL Foundation holders on key questions from the survey about how certification impacts job performance:

At my current job I use skills learned or enhanced through certification:
Several times a day: 53.2 percent
Several times a week: 29 percent
Several times a month: 6.5 percent
Occasionally: 9.7 percent
Rarely: 1.6 percent

Since becoming certified, I feel there is greater demand for my skills.
Strongly agree: 33.9 percent
Agree: 46.8 percent
Neither Agree nor Disagree: 16.9 percent
Disagree: 2.4 percent
Strongly Disagree:  [No responses]

Becoming certified has increased my problem-solving skills.
Strongly agree: 25.8 percent
Agree: 45.2 percent
Neither Agree nor Disagree: 21 percent
Disagree: 8 percent
Strongly Disagree: [No responses]

Becoming certified has increased my workplace productivity.
Strongly agree: 21 percent
Agree: 42.7 percent
Neither Agree nor Disagree: 25.8 percent
Disagree: 8.9 percent
Strongly Disagree: 1.6 percent