If you mean aerial drones, some number more than 670,000 UAVs have been registered by the FAA. It has been estimated that something like 1 million will be flying by the New Year 2018. I guess that some 50 industries use drones with something like 30,000+ women and men learning to be commercial, etc pilots.
1 Secondary amenorrhoea is where an established menstruation has ceasedâfor three months in a woman with a history of regular cyclic bleeding, or nine months in a woman with a history of irregular periods. 2  This usually happens to women aged 40â55.
Amenorrhea in athletes, sometimes called exercise-associated amenorrhea, occurs when a woman doesn't have a regular period either because she exercises too much, eats too few calories or both. 1  In order to have regular periods women need to consume a certain number of calories and maintain around 16 percent body fat or more. If a woman has too little body fat the ovaries stop producing estrogen and the woman stops menstruating.