HONOLULU -- Prostitution is on the rise in Honolulu, and what you can see on the street is only a small percentage of what is happening, law enforcement officials said.

There is no exact number of how many prostitutes there are in Honolulu.

However, you can estimate the rise in the number of arrests. Last year, the Honolulu Police Department arrested 477 adults on charges of prostitution. That is 79 more than in 2006.

The increase of prostitution in Waikiki can be attributed to several factors, including the Internet.

A drive into Waikiki at night will give you an eyeful.

The weather, economy and an ever-moving industry are factors as to why the islands may be seeing more women selling sex.

"Honolulu is part of what we consider the western circuit, and it's a moneymaker here," FBI Special Agent MK Itnyer said.

Only about 10 percent of the sex work is being done on the street, experts said.

"So, for every one prostitute that you see on the street, there's going to be at least 10 more who are either working a book, which means they have their own number, or they work on the Internet," Waikiki outreach worker Pam Vessels said.

The FBI said one of the oldest professions is now turning high tech.

"Here in Honolulu we have very active tracks, but in conjunction with that the Internet is being used extensively," Itnyer said.

The Internet makes it easier to avoid arrest and to exploit juveniles who usually will not be walking the streets, the FBI said.

"There is a demand for young-looking girls, and the most vulnerable that we find are the runaways and the throwaways," Itnyer said.

Law enforcement officials are targeting the pimps in an effort to break up prostitution rings, especially those who recruit juveniles.

However, authorities face a daunting task.

"Here in Honolulu, with the assistance of HPD, I've been able to identify at least 56 pimps," Itnyer said.

Social workers say it is an industry that's not about to go away.

"There's always going to be sex work because there's always going to be men who want to pay for sex," Vessels said.

Here are a few more statistics on prostitution from the FBI:

The FBI states the average age of entry into prostitution is 14-years-old.

The average life expectancy of a prostitute is 5 to 7 years.