Smoking is on the Decline in Cancer City

The line chart about smokers of cancer city from 1990 to 1997.As can been
seen from the chat ,there is a stable decrease of smokers of cancer city. The point
represent the number of smokers aged 35-45,while the triangle stand for the number
of smokers aged 20-34.
Cleary,there was a contant decline of smokers in the city. those aged 20-34 numberd 1500,during 7 years drop off 5000.There are only 10000 somkers in 1997.Similar older smokers aged 34-45 decrease 14000 especially only 6000 smokers pepole smokeing in 1997.
I think that there are three reasons could explaind this situation. First of all, with the development of economic and society ,people also improve theri health conutiously.It is require that they should give up habits .For example smoking.Secondly ,people realize that smoking could pollute environment and influence other people's health. Finally,It is also reason that price if cigrette increasing rise .this is lead to some people abandoned smoking.
Judging from all the evidence offered .We can safely arrive at the conclusion that smoking is on the deline not only in cancer city but in the whole world in the near future.

Smoking is on the Decline in Cancer City

The line chart is about smokers of cancer city from 1990 to 1997.It can been seen from the chart that there is a steady decrease of the smokers of cancer city. The point represents the number of smokers aged from 35 to 45,while the triangle stands for the number of smokers aged from 20 to 34.
Obviously,there was a sharp decline of the smokers in the city. those who aged from 20-34 once numberd 15000 ,during 7 years it reduced by* 5000.Thus,there are only 10000 smokers in 1997.Meanwhile,the number of the older smokers aged from 34-45 has cut down to 14000 ,only 6000 smoking in 1997.
I deem* that three reasons may explain the phenonmenon. First of all, with the development of economy and whole society ,people are desiring for improving their living-standerd in a row.It is required that they must give up their indulgences .Such as smoking.Secondly ,people come to realize that smoking will pollute the environment and do harm to other people's health. Finally,the price of the cigrettes is sharply on the rise ,all of which lead to some people abandoning smoking.
Judging from all the evidence offered .We can simply arrive at the conclusion that smoking is on the deline not only in cancer city but in the whole world as well in the near future.

drop off解释为一个一个的离开．而不解释为减少