Population

The term population refers to the total number of individuals inhabiting a planet, country, colony, or settlement.

Planets with signs of refined metals and alloys were a good indicator of possessing a population, as was suggested by T'Pol upon discovering the remnants of the planet Xindus. 

When the con artist posing as Ardra first appeared to the Ventaxians in 2367, she presented a form containing guidelines "for a full census of the population with emphasis on productivity and economic forecasts" of the planet Ventax II. 

Gains
The only thing that kept the tribble population in check on Iota Geminorum IV was that planet's abundance of reptiles. When left unchecked, a few tribbles can quickly multiply into numbers exceeding several thousands, as was the case on Deep Space Station K-7. In 2368, a population of 1,771,561 had established itself on the station, a figure that was determined by assuming "that one tribble multiplying with an average litter of ten producing a new generation every 12 hours over a period of three day.

During the mid-23rd century, the planet Gideon suffered from an extreme case of overpopulation. Gideon ambassador Hodin explained the cause of this, stating that, "the birth rate continued to rise, and the population grew, until now Gideon is encased in a living mass...who can find no rest, no peace, no joy."

When the threat of a Skorr jihad was revealed in 2270, Spock calculated that in two standard years, the Skorr would be capable of breeding an army of 200 billion warriors. 

Losses
According to Spock, 6 million people died in Earth's first World War, 11 million in the second World War, 37 million in the third World War. Phlox, and later Jonathan Archer, stated that, officially, 30 million people died in the Eugenics War. William T. Riker, as well as Seven of Nine, stated that 600 million were killed in World War III. The Xindi attack on Earth resulted in 7 million human casualties. (, et al.)

During the Denobulan-Antaran wars, Denobulan battle tactics resulted in 20 million Antaran casualties. 

The mutagenic virus created by the Loque'eque infected tens of millions of people on Tret's homeworld, all of whom were destroyed. 

Twelve million Valakian died on the planet Valakis in 2149, as a result of an unknown plague. 

By the 2260s, war casualties among the civilian population of Eminiar VII were totaling from 1 to 3 million dead each year from direct enemy attack during the Eminiar-Vendikar War. 

During the Federation-Klingon War, which occurred in an alternate timeline, the Federation had amassed 40 billion casualties between 2344 and 2366. 

Dukat was responsible for the deaths of 5 million Bajorans during the Occupation of Bajor. In all, it was determined that as many as 15 million Bajorans were killed during the Occupation. 

The population of the inhabitants of the dimensionally shifting planet Meridian had dwindled to about thirty by the year 2371 due to the fact that the people could only reproduce while in their humanoid form, and their time in normal space was constantly growing shorter. 

Over 4 million Borg drones were killed in the Borg-Species 8472 War. 

In 2374, Julian Bashir and the group of genetically engineered from the "Institute" that he worked with, calculated that before the Dominion War was over, the Federation would suffer 900 billion casualties in the years to come. 

In the final days of the war, the Dominion eliminate 2 million men, women and children when they destroyed Lakarian City. In all, they annihilated over 800 million of the inhabitants of Cardassia Prime. Prior to that, over 7 million Cardassian soldiers had given their lives in the war. 

Demographics
One out of every fifty million of Tarquin's species were born telepathic on Tarquin's homeworld. Those who are born telepathic are considered a threat to the rest of the population. 

During the early 21st century, six of the eight Human blood types accounted for three quarters of Earth's population. 

The planet Vulcan had over one million physicians during the mid-22nd century. 

During the mid-22nd century, Vissian cogenitors made up about 3% of the planet Vissia's population, which was described as being "a perfect ratio" in the terms of being natures way "of finding the right balance." 

Nearly half of the Trill population was capable of being joined with a Trill symbiont. 

During the late 24th century, Grand Nagus Zek claimed that females made up 53.5% of Ferenginar's population, yet contributed virtually nothing to the gross planetary income. 

Population figures
The population figures of various colonies, planets, or civilizations throughout the Milky Way Galaxy.