Each line (link) is for a specific period. April 4 is for the short sales from Mar 16th to end of month. Mar 26 (which seems late to me would cover the period from Mar 1 to 15th.
Mar 1 - 15 Mar 16 - 30
short trades 4976 1335
%total trades 9.45% 14.58%
Short volume 1, 634,000 5,974279
% total volume 12.43% 19.18%
Short value $2,646,772 $10,156,806
% traded value 12.47% 19.19%
So you can get all kinds of useless (lol) info from this. eg. new shorting decreased in the last 1/2 of the month. I would assume the reason is that the SP was down. Fewer starting/adding to a short position. Stats have nothing to do with the total accumulated number of shares shorted, except that they affect the totals.