Linear regression lines fitted to the beac 

 significance of the long-term trends. (Se 

 and App. C.) 



volume trends and statistical 

 Sec. Ill, 6 for explanation 





Estimated 











Profile line 



coefficient 



Y Intercept 



r' 



Significance^ 



Trend' 



1^ 

 23 













33 







^ 







43 













S3 













8 



-0.52 



151.59 



0.14 



0.001 



- 



10 



0.16 



- 27.49 



0.03 



0.20 



* 



12 



6.74 



-2203.28 



0.68 



0.001 



* 



13 



1.09 



- 489.12 



0.06 



0.10 



* 



14 



4.08 



-1399.52 



0.88 



0.001 



* 



15 



-0.05 



- 85.93 



0.001 



0.90 



- 



16 



0.04 



46.60 



0.001 



0.001 



+ 



17 



1.26 



- 232.90 



0.31 



0.001 



* 



18 



5.47 



-1743.74 



0.92 



0.001 



* 



^+ , accretion ; - , erosion . 



^The lower the number, the hiRher the significance; e.g., 0.001 indicates that the 



erosion or accretion trend is not due to chance at the 99.9 percent level. 

 ^Data does not meet basic assumptions. 



56 



