the sales of vehicles by color from 1987 to 2001 The line graph indicates the sales of vehicles from 1987 to 2001. The horizontal axis represents years and the vertical axis represents percentage of this sales. The line graph presents both the increase and decline in sales for green and blue colours, as sales fluctuated during the fourteen-year period. First of all, of all years except for the years between middle of 1993 and late of middle of 2000, blue vehicles' sales was more than green ones. For blue vehicles, there was stable from 1987 to 1988, then there was a fall step by step until middle of 1990. During 2-year period, there was increase from 17% to 23%. Between 1992 and 1997, there was a decrease to 10. After a little a rise, there was stable from middle of 1998 to 2001. Lastly, green vehicles' sales were little fluctuations until middle of 1989. Starting in 1989, there was a rise sharply and got to the peak by 30% sales' rate in the middle of 1996. Green vehicles declined steeply by 20% until 1998. There was a bit rise during a year period. There was a decreased again in the middle of 2000. After than sales went stable. To sum up, both of the sold vehicles colours vary from period to period as independent of each other during the fourteen-year period. (221)