You might have noticed the decreased number of detection rules also visualized in our chart below, showing the "No. of Detection Patterns". Our detection team keeps checking old detection rules for improvement constantly.
Thanks to our latest methods we replaced a lot of rules with fewer, more efficient ones. This optimization procedure accounts for the drop in the graph. Hence we have been able to reduce the size of the weekly updates without decreasing the detection rate itself. Additionally we have been able to speed up the whole scan as you might have experienced already.