According to data put together by Harvard's Amitabh Chandra, which the New York Times published in raw form in 2006, it was the least common birth date for more than two decades in the late 20th century; September 16 comes in at the other end of the spectrum, as the most common date for babies to be born.
A Goldfish will grow quicker if you increase its metabolism slightly. This can be done by keeping the water at summer temperatures of around 65F to 70F. Goldfish kept at this higher temp will also need added space (2 gals per inch of fish), air bubbles and a really good filtration system.
Fish breeders may find that by mimicking the natural seasonal changes and raising the goldfish water temperature slightly in the spring to around 25 or 26 degrees centigrade, and lowering the temperature to between 10 and 12 degrees in the winter, that their fish breed more easily and produce healthier, hardier larvae.