Fluctuating turbo pressure (with graph-readouts)
 

I own a V70 2004 2.0t B5204T5 with a very fluctuating turbo pressure. The turbo builds up good pressure, but the pressure drops suddenly and the builds up again. This goes on until you ease down on the throttle.
VIDA dosent show any related errors. I've been reading out the turbo pressure while driving in different fashions and posted the graphs below. The only graph that includes gear change is the second graph which was a kick-down.
Graph 1: Gentle acceleration from 70-80km/h, 4 gear:
https://s32.postimg.org/ze207gpvp/20160715_203754.jpg
Graph 2: Kick-down from 0. 1-4 gear:
https://s31.postimg.org/gtwuowtnf/20160715_204843.jpg
Graph 3: Acceleration steep uphill, 40km/h~, 2 gear.
https://s32.postimg.org/h7yelqath/20160715_205206.jpg
Graph 4: Acceleration from gentle uphill 80km/h~, 3 gir
https://s32.postimg.org/5bq1crzh1/20160715_205842.jpg

The acceleration of the dies off in relation with the graph.

Any advice? Thanks in advance.