Municipality Trebnje, which is part of the Jugovzhodna Slovenija statistical region, measures 195 km2; this ranks it 28th among Slovene municipalities.
Statistical data for 2010 reveal the following:
In the middle of 2010 about 14,650 people (about 7,500 men and 7,150 women) were living in the municipality, which ranks Trebnje 37th among Slovene municipalities. The population density was 75 people per square kilometre, which was lower than the national average of 101 people per square kilometre.
The number of live births was higher than the number of deaths, which means that natural increase per 1,000 population in the municipality was positive. It was 2.9 (in Slovenia 1.8). The number of people who moved from the municipality was higher than the number of people who moved into the municipality, so net migration per 1,000 population in the municipality was negative. It was -3.6. The sum of natural increase and net migration per 1,000 population in the municipality was negative. It was -0.7 (in Slovenia 1.6).
The mean age of people in Trebnje was 39.8 years, which was lower than the national average (41.6).
In contrast to most Slovene municipalities, in Trebnje the number of young people was higher than the number of old people: there were 94 people, aged 65 or more, per 100 people aged 0–14. This ratio shows that the value of the ageing index was lower than the national average of 117. It also shows that the mean age of people in Trebnje is growing more slowly than in Slovenia as a whole. Data by sex show that the ageing index for women was in all Slovene municipalities higher than the ageing index for men. In Trebnje – as in most Slovene municipalities – more women were 65+ years old than 14 or less; for men the situation was exactly the opposite.
Trebnje had 3 kindergartens. They were attended by 573 children or 71% of all children aged 1–5, which was less than the national average of 74%. In the school year 2010/2011 elementary schools in Trebnje were attended by about 1,300 pupils, while various upper secondary schools were attended by about 620 pupils. There were 61 students and 10 graduates per 1,000 people in the municipality; in Slovenia the averages were 52 per 1,000 and 10 per 1,000, respectively.
Among people aged 15–64 (i.e. working age population) about 65% were persons in employment (i.e. persons in paid employment or self-employed persons), which is more than the national average of 59%.
The registered unemployment rate was 7.7%, which is less than the national average (10.7%). As in most Slovene municipalities, more women than men were unemployed.
In Trebnje, average monthly gross earnings per person employed by legal persons were about 9% lower than the annual average of monthly earnings for Slovenia; and net earnings about 7% lower.
Every 35th person in the municipality was receiving at least one financial social assistance. In Slovenia as a whole every 22nd person received at least one financial social assistance.
The value of gross investment in new fixed assets in the municipality (EUR 3,900 per capita) was higher than the national average (EUR 2,176 per capita).
In 2010, there were 443 dwellings per 1,000 population. About 54% of dwellings had at least three rooms. Average size of dwellings in the municipality was 79 m2.
About every other person in Trebnje had a car (57 passenger cars per 100 population); cars in this municipality were on average 9 years old.
In 2010, 372 kg of municipal waste per person was collected in Trebnje, which is 17 kg less than on average in Slovenia.