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)。