New statistics released by the Air Force suggest the air war against the Islamic State militant group is expanding — perhaps even more so than most observers realize.

For only the second time since Operation Inherent Resolve began in August 2014, the service dropped more than 3,000 munitions in one month in December. The other time? The month prior, in November 2015.

The statistics are available online, but Checkpoint has compiled them in this chart for easier understanding. A caveat: It’s worth noting that the amount of bombs dropped by partners like Britain is not reflected here. Neither are airstrikes carried out by the U.S. Navy, which has handled a fraction of the air war from aircraft carriers stationed on a rotational basis in the Persian Gulf.

Plotted this way, the numbers suggest a couple of specific phases in the operation. In January, there were more than 2,400 weapons dropped — more than in each of the next five months. That time corresponded with a period in which Kurdish forces known as the peshmerga launched a military offensive to recapture the Syrian border town of Kobane and surrounding territory from the militants.

The monthly numbers held steady just under 2,000 weapons released in March and April, as the Iraqi military carried out an operation to retake the city of Tikrit. It dipped to its lowest monthly number of the year in June with 1,683 weapons released, but jumped to 2,823 in July, as Iraqi forces launched an offensive in Anbar province.

The number of weapons released climbed over 3,000 in November and stayed that high in December. While operations were ongoing throughout Iraq and Syria, that time period includes offensives on the ground to take back the city of Ramadi in Iraq and the Tishreen Dam in Syria.

A couple of footnotes: A weapon released does not equate to an individual airstrike in the military, although it can on occasion. Some airstrikes include numerous weapons on a single target, or related set of targets. In 2015, the Air Force flew 9,908 missions in Iraq and Syria in which at least one weapon was dropped. It released 28,714 weapons overall, according to service statistics.

For comparison’s sake, here’s a graphic showing how many weapons were dropped in Afghanistan each month in 2015. It’s strikingly different, reflecting the shrinking U.S. mission there despite ongoing concerns about how badly security has crumbled in parts of the country:

The total number of weapons released in 2015 by the Air Force in Afghanistan was 947 — smaller than in any single month in the campaign against the Islamic State. The outlier month in Afghanistan was October, with 203 weapons released. That’s the same month that 63 airstrikes were launched in a single operation in southern Helmand province to take out what U.S. military officials described as an al-Qaeda training camp.