The line graph illustrates the proportions of three most-registered types of commercial vehicles in the US between 1970 to 2010.
Overall, truck registration generally accounted for the largest share of the total registration, although experienced a notable decline. A similar downward pattern can be observed on bus figure, which remained the least proportion throughout the period. Meanwhile, dramatic fluctuations can be seen on taxi registration over the 40 years.
Turning to the proportion of truck registration, it started as the largest contributor in 1970, approximately making up half of the total proportions, before declined significantly in the following decade, hitting a low of roughly 30%. Thereafter, the figure rose consistently from 1980 to 2010, eventually reaching nearly 45%. In contrast, the bus registration began at a lowest proportion of around 5% in 1970 and gradually climbed to roughly 15% in 1980, achieving a two-fold increase, after which it progressively shrank for 30 years, dropping to around 3% by the end of the period.
As for the proportion of taxi registration, it steadily went up in the first decade, from just under 25% to a peak of approximately 35%, then considerably decreased to 15% in 2000, before it rebounded quickly in the last decade, surging to roughly 35% by 2010.