MADRID, Spain – How many sex workers must a Spanish brothel employ in order to turn a profit? What does each prostitute earn per client, and how many clients do they see per day?

Spain’s National Statistics Institute (INE) wants to know, in order to determine how much brothels contribute to the country’s gross domestic product. The reason? European Union member states must report the percentage of GDP generated by illegal activities including sex work, drugs and smuggling. The EU edict sets 2016 as the reporting deadline.

In pursuit of the goal, INE’s paper-pushers have been calling the national brothel organization Anela — yes, illegal Spanish brothels have their own trade group — to get hard data.

Anela spokesperson José Roca thought the first call was a joke, according to a report in Spain’s El País newspaper. After INE’s bureaucrats convinced Roca they weren’t kidding, he answered their queries.

• Spanish brothels must employ 50 or more prostitutes to be viable.
• The average price per sessions ranges from 40-70 euros.
• Each sex worker sees between four and eight clients daily.

Why does the EU want the data? According to the UK’s Guardian newspaper, the EU has established a debt ceiling of 3 percent of GDP. The bigger the member state’s GDP compared to its public debt, the lower the percentage will be. Legal or not, every bit of revenue helps bolster the GDP, allowing countries to accrue more debt for infrastructure expansion and repairs, public assistance and legislative junkets.

The UK’s Office for National Statistics, for example, said the combined revenues of sex work and the illegal drug trade contributed £9.7 billion to Britain’s GDP in 2009, the most recent year for which data is available. The figure, split £5.3 billion and £4.4 billion respectively, helps put the debt percentage at 0.7 percent of the UK’s GDP.

Spain’s best estimate indicates 300,000 sex workers operate in the country. If the figure is accurate, prostitutes are quite busy: In a country with a population of about 23 million males, 39 percent have admitted to hiring sex workers at one time or another. Meanwhile, law enforcement officials estimate prostitution contributes as much as 10 billion euros annually to Spain’s GDP.

Roca indicated he thinks attempting to pin down more reliable data is a waste of time.

“In reality, it’s impossible to calculate,” he told El País. “There is no census of prostitutes nor clubs nor the number or cost of services. You might as well pick a number.”