Population and Households
The population of Irosin as of August 1, 2015 was 56,662 based on the 2015 PSA Census of Population. Irosin’s population is higher by 4,885 compared with the population of 51,777 in 2010, and by 11,155 compared with the population of 45,507 in 2000. The rate at which the population grew during the period 2010 to 2015 was 1.72%. Irosin’s population accounted for 7.15% of Sorsogon province total population of 792,949 and ranked sixth in terms of number of population. There are 11,978 documented households in the same year and the average household size is 4.73. The population for the year 2018 is projected to be 59,658 and the number of households is 12,613.
Irosin’s population is expansive, that is, a very large proportion of population belongs to the younger age group. In 2015, the age group below one-year to 14 years old accounted for 36.12% of the total population. This kind of population structure is brought about by high fertility since new births are naturally added to lower age group. There is a trend of decreasing fertility as the proportion of age group below 14 years old declined from 44% of the local population in 1990, to 42% in 2000, and to 39% in 2010. The productive population with ages ranging from 15 to 64 years old comprise 59.58% of the total population in 2015, from 54% in 2000 and 56% in 2010. In comparison with national data, the proportion of productive age is 62% of the total population in 2010. Senior citizens accounted for 7.95% of the local population. (Refer to Table DE-1 and DE-2).
Male population is slightly higher than the female population during the census year 2010 and 2015. There are 103 males for every 100 females. The local age-sex distribution follows a worldwide pattern in which males predominate at birth but the ratio gradually declines with increasing age presumably because males have higher age-specific mortality rates. Consequently, females tend to outnumber males as their age advances. For the age group 65 and above, the ratio is 64 males for every 100 females in 2015.
There is a high total dependency ratio, or the ratio of those who are too young (below 15 years old) and too old (65 years and above), to those who are 15 to 64 years, is 70 dependents and for every 100 productive individuals in 2015. The young dependency ratio is 61 young dependents for every 100 productive individuals while the elderly dependency ratio is 9 out of 100. Local total dependency ratio is declining from 92:100 in 1990, to 85:100 in 2000 and to 78:100 in 2010. About 58.58% of the total population are in the working age of 15 to 64 years old, with a male to female ratio of 104. The proportion of those in the working age is increasing from 52% of the population in 1990, to 54% in 2000 and 56% in 2010. Comparing to national data, 62% of the Philippine population in 2010 are in working age. Almost half of the population or 45% are in the school-going age of three to 22 years old. In pre-school age (3 to 6 years) are 9.58% of the population, 14.41% are in elementary school age (7 to 12 years), 13.89% are in secondary school age (13 to 18 years) and 7.43% are in tertiary school age (17 to 22 years).