Final answer:
The number of food-borne botulism outbreaks by place of food processing cannot be determined from the given information, but it is likely that the number has decreased over time due to improved food processing practices.
Step-by-step explanation:
The number of food-borne botulism outbreaks by place of food processing from 1950 to 1996 cannot be determined from the given information. However, it is mentioned that proper sterilization and canning procedures have reduced the incidence of botulism. Most cases of foodborne illness now are related to small-scale food production. Therefore, it is likely that the number of outbreaks has decreased over time due to improved food processing practices.