In which year the difference between the total sales and the gross profit is the least?

As per given above table , we have
Required difference = Total Sales − Gross Profit
In 1990 ,
= 351.6 − 155.5 = 196.1;
In 1991 ,
= 407.9 − 134.3 = 273.6
In 1992
= 380.1 − 149.9 = 230.2;
In 1993 ,
= 439.7 − 160.5 = 279.2
In 1994 ,
= 485.9 − 203.3 = 282.6
Hence required answer will be 1990 .