Fluctuation; both increases and decreases — changes in number or degree that go up and down.
売上は月ごとに増減が激しいので計画が立てにくい。
Sales fluctuate sharply month to month, so it's hard to make plans.
気温の増減が激しく、服装に困る季節だ。
The temperature fluctuates a lot, making it a season that's hard to dress for.
データの増減をグラフで分かりやすく表示した。
I displayed the increases and decreases clearly with a graph.