Not sure what those stats would be like but Moyes also had us on 21 points after 17 games in the 2011 season with an even worse GD which the stats that count at the end of the day.
Moyes managed to turn that season round and we finished in 7th, lets give Martinez a chance to do the same.
I manage to dig out some stats all the way back from 2010
2009/2010
shot on goal per game 15.5
opponent shot on goal per game 13.3
2010/2011
shot on goal per game 15.3
opponent shot on goal per game 13.3
2011/2012
shot on goal per game 13.7
opponent shot on goal per game 12.4
2012/2013
shot on goal per game 16.7
opponent shot on goal per game 11.9
2013/2014
shot on goal per game 14.8
opponent shot on goal per game 13
2014/2015
shot on goal per game 13.1
opponent shot on goal per game 13.2
you can see the general trend there mate.
Certain things that made me concern, we're having better attacking players yet our shot per game decline.
We're having lion share of possesions but yet we're allowing opponent to shoot more. Something is wrong tactically.