This is the 4558th most frequent Japanese word.
年々
"Year by year" or "annually."
In this sentence, '年々' (nennen) is used to indicate a gradual change occurring every year.
日本の人口は年々減少しています。
Japan's population is decreasing year by year.
Here, '年々' emphasizes continuous improvement over years.
彼の英語の能力は年々向上している。
His English skills are improving year by year.
In this example, '年々' highlights ongoing development over successive years.