Allot Communications blocking of vanilla Tor, obfs4, and meek in Kazakhstan, starting 2016-06
At the beginning of June 2016, direct users in Kazakhstan fell, while bridge users simultaneously rose. Thereafter, bridge users slowly declined.
The mainly used transport was obfs4.
The dip in bridge users during September was likely not related to anything happening in Kazakhstan, but is an artifact of the changeover of bridge authorities. See https://lists.torproject.org/pipermail/metrics-team/2016-September/000217.html.