21.over the period from...to...the...remained level.

在...至...期间，...基本不变。

22.in the year between...and...

在...年到...期间...

23.in the 3 years spanning from 1995 through 1998...

1995年至1998三年里...

24.from then on/from this time onwards...

从那时起...

25.the number of...remained steady/stable from (month/year) to (month/year).

...月(年)至...月(年)...的数量基本不变。

26.the number sharply went up to...

数字急剧上升至...

27.the percentage of...stayed the same between...and...

...至...期间...的比率维持不变。

28.the figures peaked at...in(month/year)

...的数目在...月(年)达到顶点，为...

29.the percentage remained steady at...

比率维持在...

30.the percentage of...is sightly larger/smaller than that of...

...的比例比...的比例略高(低)。