Pivot Table and Trendlines
 

Thanks in advance for any replies on this situation:

I have aa pivot table where it is line graph showing numbber over a period
of time. And, I add trendlines for each line. However, when I change the
graph via paging, the trendline goes away. Is there anyway, to keep the
lines even when i am changing the parameters of the analysis via the paging
funtion in the pivot chart?