The graph indicates significant changes in the share of transportation registrations of the three most typical commercial vehicles in the period from 1970 to 2010. Generally, the proportion of vehicles: bus, taxi and truck fluctuated abnormally during that period.
The first most common vehicle used for commerce was truck. Looking through the graph, it was obvious that truck was used the most as it counted for nearly 50%. However, from 1970 to 1980, the proportion dipped sharply by 30% in 1980. This was a negative change, personally. Between 1980 and 1990, the number of truck registrations had almost no change. However, from after 1990 to 2010, the proportion increased gradually and in 2010, truck stood in the first place again.
The second type of commercial transportation was taxi. The number of taxi registed was considerably less than that of truck, just about 25%. During 20 years, from 1980 to 2000, this proportion reduced uncontrollably, stopped at approximately 15% in 2000. However, from the period of 2000 to 2010, it increased one more time. In 2010, the proportion of taxi registration was about 35%, which was still lower than that of truck.
The last one was bus registration. Bus was seemingly not too popular when compared to the formers two. In 1970, it just constituted approximately 5%, which was a low number. In 1980, it increased by 15%, not a high number when compared to truck and bus. However, between after 1980 and 2010, the number no longer increased, conversely, it reduced sharply, stopping at lower than 5% in 2010.
To sum up, truck was the most common means of commercial vehicle, the least one was bus with regard to the period from 1970 to 2010. These numbers showed the propesity in vehicle registrations in US between 1970 and 2010.