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全球人口的动态变化:1955年全球有人口28亿,目前已达58亿,到2025年将达到80亿,预计每年增加8000万。1955年生活在乡村的人口占总人口的68%,生活在城市的占32%;1995年该比例为55%和45%;到2025年预计乡村人口占41%,城市人口占59%。年龄超过65岁的人数将由目前的3.9亿增至2025年的8亿,从而达到当时总人口的10%。预期寿命的演变:1955年全球人口平均寿命仅48岁,1995年为65岁,到2025年将增至73岁。例如在法国,1950年仅有200位百岁老人,到2025年预计将增长750倍,即有15万百岁老人。死亡年龄结构的改变:1955年,全球死亡人数的40%是5岁以下儿童,21%是65岁以上老人。1995年,
Dynamic changes in the global population: In 1955, the world had a population of 2.8 billion, and it has now reached 5.8 billion, and by 2025 it will reach 8 billion, which is expected to increase by 80 million annually. In 1955, 68% of the population lived in rural areas and 32% lived in cities. In 1995, the proportion was 55% and 45%. By 2025, the rural population is expected to account for 41%, and the urban population is 59%. The number of people aged over 65 will increase from the current 390 million to 800 million in 2025, reaching 10% of the total population at that time. Evolution of life expectancy: The average life expectancy of the global population in 1955 was only 48 years old, and it was 65 years in 1995 and will increase to 73 years by 2025. In France, for example, in the year 1950 there were only 200 centenarians, and by 2025 it is expected to increase by 750 times, that is, 150000 centenarians. Changes in the structure of the age of death: In 1955, 40% of the world’s deaths were children under the age of 5, and 21% were older than 65. the year 1995,