Saikai (西海市)

City

Nagasaki (長崎) — 2025 — Based on Basic Resident Register

Total Population

24,973

-464 (-1.82%)

Young (0–14)

10.1%

2,531

Working Age (15–64)

49.8%

12,428

Aging Rate

40.1%

10,014

Population Trends (2006–2025)

* Data before 2012 includes Japanese residents only (foreign residents were added to the Basic Resident Register in July 2012)

Category	Total	Male	Female
Total	24,973	12,520	12,453
Young (0–14)	2,531	1,282	1,249
Working Age (15–64)	12,428	6,834	5,594
Elderly (65+)	10,014	4,404	5,610

Year	Total Population	0–14	15–64	65+	Aging Rate
2025	24,973	2,531	12,428	10,014	40.1%
2024	25,437	2,656	12,573	10,208	40.1%
2023	25,747	2,774	12,652	10,321	40.1%
2022	26,323	2,870	13,072	10,381	39.4%
2021	26,998	2,941	13,644	10,413	38.6%
2020	27,463	2,975	14,064	10,424	38.0%
2019	27,982	3,042	14,563	10,377	37.1%
2018	28,487	3,098	14,997	10,392	36.5%
2017	29,025	3,192	15,494	10,339	35.6%
2016	29,458	3,323	15,891	10,244	34.8%
2015	29,942	3,429	16,356	10,157	33.9%
2014	30,518	3,540	16,916	10,062	33.0%
2013	30,848	3,557	17,239	10,052	32.6%
2012	31,006	3,616	17,395	9,995	32.2%
2011	31,410	3,706	17,770	9,934	31.6%
2010	31,889	3,823	17,897	10,169	31.9%
2009	32,328	3,959	18,207	10,162	31.4%
2008	32,923	4,174	18,505	10,244	31.1%
2007	33,547	4,371	18,938	10,238	30.5%
2006	34,085	4,519	19,396	10,170	29.8%