Here's a quick chart of the monthly number of submissions to Reddit over time (until April 2017): https://docs.google.com/spreadsheets/d/1d3kqAebZiUqmI-GbmvNY...

At about the start of 2017, Reddit saw a noticeable increase in the activity growth rate, which investors love (although the biggest chunk occurred around October/November 2016, due to the U.S. Election)

And here's the BigQuery to reproduce the aggregation:

   #standardSQL 
   SELECT DATE_TRUNC(DATE(TIMESTAMP_SECONDS(created_utc)), MONTH) as mon, COUNT(*) as num_submissions
     FROM `fh-bigquery.reddit_posts.*`
     WHERE (_TABLE_SUFFIX BETWEEN "2015_12" AND "2017_04" OR _TABLE_SUFFIX = "full_corpus_201512")
     GROUP BY mon
     ORDER BY mon