Sales decreased by approximately 20 percent last year.

销量去年下降了约20%。

The price of wheat has decreased by 15%.

小麦价格降低了15%。

The number of new students decreased from 210 to 160 this year.

今年新生人数从210减少到160。

Fatal road accidents have decreased in frequency over recent years.

近年来致命交通事故发生率已经下降。

The number of young people obtaining qualifications has remained static or decreased.

获得各种资格证书的年轻人的数量一直保持不变或者已经减少。

The combination of hot weather and decreased water supplies is hurting many industries.

天气炎热和供水减少这两个因素结合在一起对很多行业造成了损害。