Code:

Reading nPosts DiffPrev nDays AvgPosts/day
27/11/2018 48.230.858 1.080.277 35 30.865
23/10/2018 47.150.581 944.278 26 36.318
27/09/2018 46.206.303 1.517.366 32 47.418
26/08/2018 44.688.937 1.845.193 31 59.522
26/07/2018 42.843.744 2.245.888 34 66.056
22/06/2018 40.597.856 2.190.432 28 78.230
25/05/2018 38.407.424 3.016.289 31 97.300
24/04/2018 35.391.135 2.354.827 31 75.962
24/03/2018 33.036.308 2.185.262 29 75.354
23/02/2018 30.851.046 2.002.593 29 69.055
25/01/2018 28.848.453 1.864.380 29 64.289
27/12/2017 26.984.073

What we can see is that the average per day (recent averages, comparing one reading to that of the previous month) increases until end of May, and then starts declining with September and October in the lead if we turn the drops into percentages (drops in number of posts since May are in the 10% to 23% area, depending on the month).