The following table shows the monthly rainfall data (in cm) in India during the first four months of the years 2001-2010.

All India Monthly Rainfall Series

YEAR	JAN ↑↓	FEB ↑↓	MAR ↑↓	APR ↑↓
2001	6.7	11.6	19.9	44.6
2002	17.1	20.1	23.8	38.6
2003	7.3	42.3	36.7	36.6
2004	25.1	10	12.8	55.2
2005	28.1	41.8	42.5	37.7
2006	17.7	11.9	35.6	32.7
2007	1.7	36.7	35.2	30.6
2008	18.4	19.3	41.2	29.5
2009	12	12	14.2	25.1
2010	7.5	17	14	39

Find the positive difference between the decadal average rainfall during the month of January each year and the decadal average rainfall during the month of April each year.