The number of reported allegations of sexual assault on cruise ships that operate in the US is up 32% this year through the end of September, according to the US Department of Transportation (DOT).

There were 79 reported allegations of sexual assault on cruise ships through the first 9 months of this year, up from 60 during the same period in both 2018 and 2017. Seventy-six percent of the reported sexual-assault allegations from this year through September involved passengers.

The Cruise Lines International Association, a trade group for the cruise industry, did not immediately respond to a request for comment. In April, the organization told Business Insider, in response to a story about reported allegations of sexual assault on cruise ships, that 11.9 million people from the US took a cruise in 2017, and that the group projected 28.2 million people from the US took a cruise in 2018.

Sexual assault had been reported by cruise lines more often than any other crime since at least 2016, according to an analysis from Meg O'Connor published by the Miami New Times in April.

Some crimes are not reported to the DOT because they do not fall under the categories included in the agency's cruise-ship crime report, according to the Miami New Times. A review by Congress members of crimes reported by cruise lines to the DOT and to the Federal Bureau of Investigation (FBI) in 2011 and 2012 reportedly found that cruise lines reported 30 times the number of crimes to the FBI that they did to the DOT.

Of the 149 sexual crimes cruise lines reported to the FBI in 2011, 64 were not categorized as rape or sexual assault, which means they did not have to be disclosed to the public, according to the Miami New Times' report.

Have you worked on a cruise ship? Do you have a story to share? Email this reporter at mmatousek@businessinsider.com .

NOW WATCH: Why Tesla's Model 3 received top crash-test safety ratings

See Also:

SEE ALSO: A lawyer reveals a legal nightmare you can face on a cruise ship