プログレッシブ和英中辞典(第4版)の解説
ぞうげん【増減】
increase and [or] decrease；〔変化〕variations, fluctuation(s)
増減する increase and [or] decrease；〔変化する〕vary, fluctuate
人員の増減
fluctuations [change(s)] in the number of personnel
売り上げは月によって増減がある
Our sales vary from month to month.／Our sales fluctuate each month.
大都市の人口は増減が少ない
The population of large cities does not change [increase or decrease] very much.
体重の増減
variation in one's weight／gains and losses in weight