plotraster n points in UDs too low

[SimonDedman]

Running plotraster on the default dataset:
"1.61% of location points within 50% contour"
"19.65% of location points within 95% contour"

check these, shouldn't be so low surely??
Can plot them, QGis?

UD95:

UD50:

[SimonDedman]

Could b a function of highly dispersed examples above, vs more clustered typical examples?