Last week, a University of Ottawa law professor got a set of documents from the Canadian government showing that law enforcement agencies are asking the country's telecom operators for subscriber information every 27 seconds.

That's a staggering amount, but how does it compare to the United States, where authorities are willing to record all of the calls that take place in a foreign country?

To get a sense, I decided to take a look back at the transparency reports from major U.S. phone companies. In 2013, AT&T and Verizon together received more than one request every 60 seconds.

Is that a lot? Depends. It's not as high as the rate cited in Canada. But we're also dealing with an incomplete data set here.

In its first-ever transparency report, AT&T reported receiving 301,816 requests for user data from state, local and federal authorities. Verizon's inaugural transparency report, meanwhile, shows it got 321,545. That's the equivalent of 1.2 requests every minute.

But there are, of course, many other telecom operators in the United States that haven't disclosed any information on government data requests. Companies like CenturyLink and Frontier, for example. Factor those in, along with the data requests submitted to wireless operators, and the number would likely be much higher.

We actually do have data from the four major wireless carriers. AT&T, Verizon, Sprint and T-Mobile (along with a few others) submitted detailed responses to a congressional probe on data requests by Sen. Ed Markey (D-Mass.) last year. AT&T's mobile division, for instance, told Markey that it got 562,000 requests for user information, while Verizon said it got around 270,000. T-Mobile reported 297,350, and Sprint declined to give a specific number.

Problem is, this data is from 2012, so it can't be combined with the most up-to-date information from landline providers. (The landline phone companies, meanwhile, don't have transparency reports for data collected in 2012). You could get a pretty decent understanding of the wireless industry though, minus Sprint — it works out to about 2.2 requests every minute, according to the 2012 data disclosed above.

Verizon declined to comment. AT&T did not immediately respond to a request for comment.