Synoptic chart of Spanish political system.

 

Spanish population pyramid

A population pyramid is a graph that representing the structure of the population into age groups and sex groups .

To make a population pyramid  need to know the number of its inhabitants, expressed in percentages.

population density

Population density (in agriculture standing stock and standing crop) is a measurement of population per unit area or unit volume. It is frequently applied to living organisms, and particularly to humans. It is a key geographic term.

model of population cycle

The model of demographic transition progresses in four stages:

-Old or preindustrial demographic regime: it is characterized by high mortality rates and birth rates.

-First transition: Keep the high birth rate, but mortality drops.

-Second transition: the birth rate begins to decline, but mortality is still down more slowly.

-Modern demographic regime: Mortality rates and very low birth.

world population distribution

The world population is the total number of living humans on the planet Earth. As of today, it is estimated to be 6.975 billion by the United States Census Bureau. According to a separate estimate by the United Nations, it has already exceeded 7 billion. The world population has experienced continuous growth since the end of the Great Famine and Black Death in 1350, when it stood at around 370 million. The highest rates of growth increases above 1.8% per year were seen briefly during the 1950s, and for a longer period during the 1960s and 1970s. The growth rate peaked at 2.2% in 1963, and had declined to 1.1% by 2009. Annual births peaked at 173 million in the late 1990s, and are now expected to remain constant at their 2011 level of 134 million, while deaths number 56 million per year, and are expected to increase to 80 million per year by 2040.Current projections show a continued increase in population (but a steady decline in the population growth rate), with the global population expected to reach between 7.5 and 10.5 billion by 2050.