Many businesses here have been implementing social distancing measures for over two weeks, especially the big tech companies which moved as many employees as feasible to work-from-home shortly after the start of March.Ok, but still, these changes now would be reflective of infections almost 2 weeks ago. Not reflective of any recent measures taken, like social distancing.
It's hard to be sure how accurate any numbers are, but it's possible that the efforts here are having a visible effect on the growth rate by now.