TABLE B-7. - -Long-term trend in May and July pond indexes by strata, 
southern Alberta, May and July, 1955 to 1964 
[Index numbers in thousands] 
Stratum 
Total 
Year 
A 
B 
C 
May; 
1954- 
434 
607 
122 
1, 163 
1955- 
405 
656 
191 
1,252 
1956- 
353 
598 
116 
1, 067 
1957- 
187 
442 
82 
711 
1958- 
255 
431 
120 
806 
1959- 
131 
253 
120 
504 
I960- 
257 
550 
193 
1,000 
1961- 
191 
432 
69 
692 
1962- 
118 
345 
60 
523 
1963- 
170 
602 
72 
844 
1964- 
138 
366 
137 
641 
Average, 1952-64- 
262 
491 
120 
874 
Percent change, 1964 from - - 
Average- 
-47 
-25 
+14 
-27 
1963- 
-19 
-39 
+90 
-24 
July: 
1954- 
241 
400 
65 
706 
1955- 
218 
339 
66 
623 
1956- 
185 
420 
64 
669 
1957- 
120 
288 
42 
450 
1958- 
136 
282 
53 
471 
1959- 
93 
140 
74 
307 
I960- 
84 
262 
57 
403 
1961- 
51 
153 
35 
239 
1962- 
65 
257 
48 
360 
1963- 
145 
471 
73 
689 
1964- 
78 
162 
72 
312 
Average, 1952-64- 
164 
302 
70 
536 
Percent change, 1964 from - - 
Average - 
-52 
-46 
+2 
-42 
1963- 
-46 
-66 
-2 
-55 
56 
