Population in Kocaeli, Sakarya, Düzce, Bolu, Yalova 22 indicators covering population for Kocaeli, Sakarya, Düzce, Bolu, Yalova. IndicatorLatest Year10-yr change Rank Population on 1 January by age group, sex and NUTS 2 region 4.29 million 2025 up 21.7% 78th Population on 1 January by age, sex and NUTS 2 region 4.29 million 2025 up 21.7% 79th Animal populations by NUTS 2 region 528.7 2025 — 125th Live births (total) by NUTS 3 region 44,865 2024 down 18.9% 62nd Population density by NUTS 3 region 212.1 2024 up 22.8% 664th Population on 1 January by broad age group, sex and NUTS 3 region 4.29 million 2025 up 21.7% 81st Live births by mother's age and NUTS 2 region 44,865 2024 down 18.9% 60th Fertility rates by age and NUTS 2 region 1.41 2024 down 27.4% 213th Population in private households by educational attainment level and 3,224 2025 up 25.1% 77th Population in private households by educational attainment level and 16.1 2025 down 56.5% 180th Population change - Demographic balance and crude rates at regional 26,369 2024 down 27.6% 66th Population in private households by educational attainment level 47.1 2025 down 24.8% 40th Population in private households by educational attainment level 47.1 2025 down 24.8% 40th Private households by degree of urbanisation and NUTS 2 region 1,359 2025 up 35.8% 116th Population on 1 January by age group, sex and NUTS 3 region 4.29 million 2025 up 21.7% 80th Pupils from age 4 to the starting age of compulsory education at 75.7 2024 up 39.2% 299th Live births by age group of the mothers and NUTS 3 region 44,865 2024 down 18.9% 62nd Pupils from age 3 to the starting age of compulsory education at 57.6 2024 up 45.8% 270th Ratio of the proportion of tertiary students over the proportion of 0.6 2022 down 25.0% 247th Causes of death - crude death rate by NUTS 2 region of residence 551.59 2023 up 16.3% 384th Causes of death - standardised death rate by NUTS 2 region of 1,194 2023 down 1.1% 66th Causes of death - crude death rate by NUTS 2 region of residence, 3 617.21 2023 up 35.7% 377th