An informal survey of Republican debt clocks — those constantly running tallies of the depth of U.S. government debt — shows that many of them are running fast.

While most clocks are known to be rough estimates and extrapolations of the pace of federal debt, some are off by as much as $200 billion, and few seem to agree with each other.

As of Friday, the Treasury Department's official website that tracks the sale of government securities held the public debt at $15.915 trillion. Sen. Bob CorkerBob CorkerSenate sends Russia sanctions bill to Trump's desk GOP senators: House agreeing to go to conference on ObamaCare repeal Republicans get agreement on Russia, North Korea sanctions MORE (R-Tenn.) roughly agreed with that on Monday, putting the debt at $15.918 trillion. Rep. Bill FloresBill FloresOvernight Regulation: GOP takes aim at Endangered Species Act | DOJ expands asset seizures | FCC chief denies Trump interfered on Time Warner merger | Panel votes to ease driverless car regs House votes to streamline pipeline reviews Questions grow over Kushner’s security clearances MORE (R-Texas) was also close, estimating it to be $15.927 trillion.

Rep. Ben Quayle (R-Ariz.) low-balled the debt on Monday, putting it at $15.438 trillion. But many other GOP estimates were higher. Also on Monday, the Republican Party of Milwaukee County in Wisconsin and listed the debt at a slightly higher $15.942 trillion., an apparently nonpartisan site that estimates the debt, put total U.S. national debt at $15.967 trillion on Monday. Rep. Mike Rogers (R-Mich.) agreed with that assessment.

But Republicans on the Senate Budget Committee said it was $15.994 trillion on Monday, while Rep. Michael McCaul (R-Texas) said it was $16.047 trillion.

Meanwhile, the Senate Republican Conference said it was $16.134 trillion, and the Washington County Republican Party in Nebraska said it was $16.315 trillion.