Over the past 10 years, the number of nonfarm workers rose by just 5%. But despite past decade’s painful recession and the slow job growth that has followed, several occupations have more than doubled the number of workers employed.

24/7 Wall St. compared employment figures published by the Bureau of Labor Statistics (BLS) for hundreds of occupations from 2002 and 2012. Service unit operator jobs in the energy industry quadrupled in that time. The nation’s aging population and changing energy needs played major roles in driving disproportionate job growth for many of the occupations listed. These are the 10 fastest-growing jobs in America.

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Many occupations with extreme job growth in the past few years owe at least part of their growth to the changing demographics of the United States. As the baby boom generation ages, many more people need help planning for retirement. This has driven growth of personal financial advisors jobs. Similarly, the need for personal care aides has grown because more people require help in their daily lives

An aging population also has driven job growth in many occupations that are not directly related to retirement planning and care. According to BLS Chief Regional Economist Martin Kohli, “The aging of the population is one of the factors that is driving the demand for massage therapists.” An aging population “is also a factor in the demand for coaches,” Kohli said. Many coaches work as instructors for leisure sports that retirees enjoy.

The growing Hispanic population, in conjunction with expanding international trade, are also factors behind the rising number of interpreters and translators, according to the BLS and Kohli.

But not all job growth can be explained by demographic shifts. For both petroleum engineers and service unit operators in the resource industry, the nation’s two fastest-growing jobs, growth likely is due largely to changes in the energy sector. Both the rise in oil prices, as well as the need to produce from unconventional sources, such as shale oil, have been beneficial to workers in these occupations.

To determine the jobs with the highest percentage growth in employment, 24/7 Wall St. compared data from the BLS’s Occupational Employment Statistics program for both 2002 and 2012. Only jobs with an estimated 20,000 employees or more were included. The program is intended to be a sample of the overall workforce, and estimates are subject to sampling error. The program does not count self-employed workers. Data are collected by the program over the course of several years. Only occupations that existed in both 2002 and 2012 were considered, and any occupations split-up or consolidated between these periods were excluded. Further information on each occupation came from the BLS’s Occupational Outlook Handbook.

These are the 10 fastest-growing jobs in America.