There is a wonderful study conducted in 1898 by von Bortkiewicz which provides data on the death of soldiers in the Prussian army from kicks by horses and mules. The data pertain to 10 army corps, each observed over 20 years, for a total of 200 corps-years. The following table summarizes the observed data: note that in 109 corps-years zero deaths occurred; 65 corps-years had one death, etc.: Deaths 0 12 Total Occurrences 109 65 22 3 200 Von Bortkiewicz felt that a distribution known as the Poisson distribution would describe these data well. Using that distribution, he produced the following probabilities: Deaths 0 1 2 3 4 Total Probabilities 0.543 0.331 0.101 0.021 0.003 0.999