รายละเอียดตัวอย่าง

The line graph compares three specific sources including industry, transport and households together with the total of air pollutants in the UK between 1990 and 2005. Overall, the total air pollutants, industry and households had a downward trend, whereas transport emission remained almost unchanged during the period shown. In 1990, the total air pollutants started at about 7.3 million tonnes. After decreasing slightly to nearly 7 million tonnes in 1993, it saw a strong fall to 4.5 million tonnes in 1996. In 2005, the total air pollutants dropped to 4 million tonnes. Likewise, the industry emission showed constantly over the same period. The sharpest decline occurred in both categories from 1993 to 1996. Both transport and households remained under 1 million tonnes. Initially, the household declined minimally to about 0.8 million tonnes and then there are slight fluctuation between 1996 and 2002. Finally, it then fell just over 0.1 million tonnes by the end of the period. By constrast, the transport still stayed stable during the period shown.