(CNN) -- The U.S. military death toll in Iraq for December is the second-lowest monthly death toll of the war, although 2007 has been the deadliest year for U.S. troops.
As of Monday evening in Iraq, the death toll for December was 21, higher only than the 20 U.S. troops who died in February 2004.
The year started with 83 deaths in January and 81 in both February and March. The numbers jumped dramatically in the spring, to 104 in April, 126 in May and 101 in June. Those three months were the deadliest three-month stretch for U.S. troops in the war.
As the military established its new strategy, insurgent attacks killed 78 U.S. troops in July, 84 in August, 65 in September, 38 in October and 37 in November.
The Pentagon says the monthly numbers reflect in part the effect of the "surge" -- the addition of 30,000 troops in and around Baghdad starting in midsummer.
"The surge has been very successful in its purpose, which was to reduce the levels of violence, the casualties, and to set better conditions for the important political steps that the government of Iraq very much needs to take," Maj. Gen. Kevin Bergner, the top U.S. military spokesman in Baghdad, said last week.
Also as of Monday, the U.S. government has reported 899 U.S. troops have died in Iraq in 2007, 50 more U.S. deaths than in 2004, which had been the deadliest year of combat in Iraq.
The Iraq War began in March 2003. Since then, 3,895 U.S. troops and seven civilian Defense Department contractors have died in Iraq.
Figures for Iraqi civilian deaths in December were not immediately available. But earlier this month, the Iraqi Interior Ministry reported that 538 civilians were killed across the country in November -- the lowest of the year.
While there's no way to confirm figures provided by the ministry, Iraqis say they've seen changes on the streets.
"Seven months ago, there were bodies scattered everywhere," Baghdad taxi driver Samir Hamoudi said. "But now, there is a big difference. The streets are empty of dead bodies."
In Iraq on Monday, two suicide bombs -- including one strapped to a woman -- and a roadside bomb killed at least eight people and wounded 25 in cities north of Baghdad, according to Iraqi officials.
The woman detonated her bomb near an Iraqi police patrol in Baquba, killing herself and wounding seven people, including four Iraqi police officers and three civilians, a Baquba police official said.
East of Baquba, in the city of Mandali, near the Iranian border, a roadside bomb killed two Iraqi border guards and wounded three Monday, according to Col. Ragheb al-Aumairi, a Diyala Military Operation Headquarters spokesman.
Five people died and 15 were wounded when a suicide car bomb exploded at an Awakening Council checkpoint in Tarmiya, a town about 25 miles north of Baghdad, Monday morning, an Interior Ministry official said.
Near Khalis, dozens of fighters -- whom al-Aumairi identified as al Qaeda members -- Monday attacked security checkpoints manned by Iraqi police and members of local Awakening Councils, killing one Awakening Council member, he said. Four others -- three police officers and an Awakening Council member -- were wounded. Watch how Awakening Councils are taking on al Qaeda »
Al Qaeda in Iraq fighters have launched a number of aggressive attacks against Awakening Councils in recent weeks.
The anti-al Qaeda Awakening Councils are predominantly Sunni and are sometimes composed of former militants. Many of them have been recruited by the U.S. military's "Concerned Local Citizen's Program" to work against al Qaeda in Iraq. E-mail to a friend