Edgun .25 chrony help

Hi All…Im in need of some knowledge. I purchased a Edgun .25 standard from a gentleman on this forum and was shooting it over the Crony today and was getting strings like this below. this is a 40 shot string from 200bar – 125bar: Why does the FPS jump so high towards the end of the string? I have not taken gun to the range yet to shoot at a distance so cannot comment on the accuracy yet. What speed does the .25 usually like to shoot around in your experiences. And what does this string mean? Thank you for your time.

824
824
833
833
835
829
819
827
833
823
829
828
827
831
833
826
821
829
827 150bar
836
840
837
840
851
858
872
877
887
889
892
891
897
910
905
919
918
923
921
920
930