The total sales (in thousands) of all the seven years for various batteries are:

For 4AH = 75 + 90 + 96 + 105 + 90 + 105 + 115 = 676

For 7AH = 144 + 126 + 114 + 90 + 75 + 60 + 85 = 694

For 32AH = 114 + 102 + 75 + 150 + 135 + 165 + 160 = 901

For 35AH = 102 + 84 + 105 + 90 + 75 + 45 + 100 = 601

For 55AH = 108 + 126 + 135 + 75 + 90 + 120 + 145 = 799.

Clearly, sales are maximum in case of 32AH batteries.

Required difference = [(84 - 45) x 1000] = 39000.

The percentages of sales of 4AH batteries to the total sales in different years are:

For 1992 =		75	x 100		% = 13.81%.
		543

For 1993 =		90	x 100		% = 17.05%.
		528

For 1994 =		96	x 100		% = 18.29%.
		525

For 1995 =		105	x 100		% = 20.59%.
		510

For 1996 =		96	x 100		% = 19.35%.
		465

For 1997 =		105	x 100		% = 21.21%.
		495

For 1998 =		115	x 100		% = 19.01%.
		605

Clearly, the percentage is maximum in 1997.

From the table it is clear that the sales of 7AH batteries have been decreasing continuously from 1992 to 1997.