I am comparing 3 sets of data of non-fatal injuries reported by workers in the aviation, bus, and train transportation industries over a 4 year period. My hypothesis is that workers in the aviation industry have less recordable injuries then either of the other two. What is the best statistical test to use in this comparison? My guess is that it is chi-squared, but I am not certain. I have 4 years of data with each year separated and each of the three industries separated. I just want

to ensure that I have chosen the best statistical test for this data comparison.

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