Analysis of Clean Sheets: First Half Season vs. Second Half

I have been a little surprised at the preference for the expensive defenders in my recent wildcard teams and have received a few comments to the same effect so I have taken a look at the number of clean sheets achieved in the first half of the season compared to the amount achieved in the second half for the last 8 seasons in the Premier League.
The following chart is pretty conclusive.  In all but one of the last 8 seasons (2006/07) the number of clean sheets increased  in the second half of the season compared to the first half - an average increase from ~100 clean sheets from the first 180 games to 120 in the last 180.

Furthermore, it's the home teams that see the most improvement in this respect with an increase of 22% compared to away team's 12%.

Looking at the number of clean sheets in the table below, so far this season clean sheets have been low for the league but not been as rare as you perhaps might have first thought, on a par with the last three seasons.


Conclusion: Don't overlook defensive points through the latter part of the season.
Data sourced from Football Data

Number of clean sheets per seaon in 1st half and 2nd half of season

			1st Half	2nd Half	1st Half	2nd Half
	1st Half	2nd Half	Home	Home	Away	Away
2004/05	99	120	59	76	40	44
2005/06	116	128	71	80	45	48
2006/07	117	116	72	62	45	54
2007/08	99	119	59	67	40	52
2008/09	108	139	57	89	51	50
2009/10	93	128	58	80	35	48
2010/11	91	100	60	66	31	34
2011/12	94	112	51	74	43	38
2012/13	91		59		32
2nd Half Avg. Increase		+18%		+22%		+12%