X increased/rose/grew from.. to ..
Y decreased/fell/dropped/declined from.. to..

There was a/an increase/rise/growth in X
There was a decrease/fall/drop/decline in Y

X peaked at/reached a peak of ..
Y levelled off at..
Z fluctuated between ..

X remained constant at ..

X rose gradually to reach … in 2005
         steadily
         sharply
         dramatically

There was a gradual fall to … in 2005
                  steady
                  sharp
                  dramatic

rising/soaring/falling/plummeting prices ..

X had doubled/halved by 2005

this trend continued/was reversed in …