Age - Sex Distribution
Specific age groups represent a demand for certain services. For instance, persons of "dependent" ages (generally under age 15 and over age 64) that require specialized health services and facilities, "economically productive" ages (15-64 years) will have to be provided with jobs, "female/reproductive" ages (10-45 years) may be the target of family planning programs, among others (HLURB Cookbook and RPS, 2005).
Sex affects the incidence of births, deaths, and marriages. It has also an implication on spatial mobility, work participation and occupational structure. One measure of sex composition is sex ratio, which is the number of males for every 100 females.
Of the 296,621 estimated population of Santa Rosa in 2013, there was an almost equal distribution of males (49.6) and females (50.4) as shown in Table 5-4. The sex ratio in the city was recorded at 98 males for every 100 females. In general, females tend to outnumber males as their age advances.
Table 5-4: Sex Composition, by Barangay, City of Santa Rosa, Laguna, 2013
The age structure of the population is determined in part by levels of births, deaths, and migration. Age distribution is usually depicted in a table that divides the population into groups of 5-year intervals (RPS, 2005).
Age Dependency Ratio is the ratio of persons in the "dependent" ages (generally under age 15 and over age 64) to those in the "economically productive" ages (15-64 years) in the population. It is sometimes divided into the old-age dependency (the ratio of people aged 65 and older to those aged 15-64 year) and the child dependency (ratio of people under 15 to those aged 15-64 years).
The total age dependency ratio of the city was estimated at 48 per hundred working persons in 2012. This implies that 100 working individuals would have to support 48 persons aside from themselves. For every 100 ind ividuals who are able to work in the city, there are 44 young dependents who are too young to earn a living (infants, children, and adolescents below 15 years old) and who depend on them for support. Moreover, the old dependents aged 65 years old and above constitute four percent of the economically productive population of the city.
Table 5-5: Age Composition by Five-Year Age Group, City of Santa Rosa, Laguna 2010-2040
The population pyramid provides a quick description of the relative size of the male and female population by age groups. The pyramid shows whether a population is predominantly young or old. The population of the City of Santa Rosa is expansive where large numbers are in the younger ages, as shown in the broad base of the pyramid.
Population Distribution by Age Group and Gender
In 2013, the City of Santa Rosa had a total of 104,130 school-age population, or those between the ages of seven and twenty-four, inclusive. An increase of almost 4,000 school-age individuals was recorded for the period 2010 to 2013 (Table 5-6). The school-age population comprised 35 percent of the total population of Santa Rosa.
The voting-age population (18 years old and over) accounted for 65.01 percent of the total population of the city in 2013. The voting-age population in 2010 is almost the same share at 64.99 percent.
The total number of registered voters and voters who actually vote during a particular election year are shown in Table 5-7. In the May 2010 election, the registered voters who actually voted comprised 73 percent of the total registered voters. It is 6 percent higher than the registered voters who actually voted in the 2007 election. The increased can be attributed to the massive campaign of both national and local governments to encourage first time voters to register in order to exercise their right to suffrage.
In the recent automated midterm election held in May 13, 2013, the registered voters who actually voted comprised 70 percent of the total registered voter population.
Figure 5-4: Total Registered Voters and Registered Voters Who Actually Voted,
City of Santa Rosa, Laguna, 2007, 2010 & 2013