The concept of securitization is generally associated with the Copenhagen school of security studies, which is generally taken to include Ole WÃ¦ver, Barry Buzan, and a range of other, more loosely associated, researchers.
Average annual number of employed coal miners in the United States, 1890-2014. US employment in coal mining peaked in 1923, when there were 863,000 coal miners. Since then, mechanization has greatly improved productivity in coal mining, so that employment has declined at the same time coal production increased. The average number of coal mining employees declined to 65,400 in 2015.
U.S. coal mining deaths: 1990-2011. Here are the number of coal mining deaths in the United States, from 1990 through 2010, and the fatality rate (deaths per 200,000 work hours). [Updated to 2010.] 1980: 133 deaths, .06 per 200,000 hours. 1990: 66 deaths, .04 per 200,000 hours. 1991: 61 deaths, .04.