Between 1860 and 2000 a census took place every ten years in December.

However the modern census did not take place until 1857.

The first national census of Ukraine took place only in 2001.

The first census covering the unified state took place in 1888.

The most recent census took place on December 31, 2010.

A census of Ireland had taken place every ten years beginning in 1821 until 1911.

An important change was that the census took place on February 1, 1801.

As the first census did not take place until 1924, it is difficult to quantify the population loss of the period.

According to Armenian law, a census must take place every 10 years.

By 1921, the last time the official census took race into account, about ten percent were considered to be "white".