Rearrange the parts of the sentence in correct order.
If per capita income is taken
P-as the measure then we are
Q-away from 'great power' status
R-still some distance

The correct sequence is PRQ.
The introductory part ends with "taken", which naturally requires a prepositional phrase or complement to complete the passive construction. Part P begins with "as the measure", perfectly connecting to form: "If per capita income is taken as the measure then we are..."

Following "we are", an adverbial phrase of distance or state is required. Part R ("still some distance") fits seamlessly.

Finally, the phrase "still some distance" connects with the prepositional phrase in part Q ("away from 'great power' status") to complete the meaningful sentence: "If per capita income is taken as the measure then we are still some distance away from 'great power' status."

Therefore, the correct arrangement is P-R-Q.