Y-Axis plot values

Hello,

I’m 100% new to ObsPy and sorry in advance if the question is stupid.
After going through tutorials, I wanted to start to get my hands on real data. So I created a client to fetch particular waveform data.

t_start = UTCDateTime("2021-01-07T00:30:00.000Z")
st = client.get_waveforms("CR", "ZAG", "*", "BH?", t_start, t_start+30*60) 
st.plot()

However, the Y-Axis doesn’t have “normal” scale. 0 in the middle and than corresponding + and - areas above/below.

Could someone explain me why are y-axis values as they are? I know that this isn’t ObsPy problem, but the data is returned like this upon download.

Thank you in advance and sorry for this stupid question

Regards,
Neven

So it seems that I forgot to remove instrument response in the process.