UPDATED NOVEMBER 2019 - the number have fluctuated as expected anywhere between 800k and 950k when I was researching and pinning for Inktober.
I started my 14 days with 495k monthly viewers ....I pinned everyday but I didn't always reach 10 pins. Some days it was 5 some days it was 15, it just depended on how much time and inspiration I had or was after. After the 14 days i worked out my viewers number had increased by 10% during that tine and has continued to increase as I keep pinning.
This is one of the pins I recently created and researched keywords for ( as I don't often illustrate portraits)