Gyroscope data drifts and then returns to 0

Hi, I have a set of gyroscope data reading angular velocity (rad/s) over a period of 10mins. I converted this data to degrees per second and then integrated this to find the angular position(Degrees). When plotted against time, the data drifts (as expected) but then as the 10 minute mark approaches the data quickly homes in 0 as seen in the picture below. What could be the cause of this and how would I resolve it?

[David Goodmanson]

Hi Jack,

what method did you use to integrate the data?

[Jack Upton]

I used the cumtrapz function to integrate the data