Data I collected directly:

PSI	Average Distance	PSI	Average Distance	PSI	Average Distance
15	    0.075353	        35	    0.584835	        55	   1.595755
20	    0.237913	        40	    0.763905	        60	   1.847850
25	    0.358775	        45	    1.104900		
30	    0.476250	        50	    1.325245