That was the steepest percentage decline since the Depression year of 1938, when ad spending dropped 8.1 percent.
The study also found a percentage decline in female athletic directors and administrators.
The percentage decline is based on the daily average.
A similar percentage decline is possible in data roaming charges.
I've never seen this much of a percentage decline.
The following day, the company's shares plummeted 27 percent, to $27.50, from $37.75, the largest percentage decline in Apple history.
The largest percentage decline came in cable television donations, which decreased 53 percent, to $84.9 million.
Symbol Technologies showed the largest percentage decline, falling 5, to 10 1/2.
The percentage decline was the second largest on the Nasdaq national system.
This was the largest percentage decline of any of the seven women's service magazines.