"least proportion" is a correct and usable phrase in written English.
You can use it when you want to refer to the smallest amount or proportion of something. For example, "Of all the participants, the least proportion were in favor of the new policy."
In the mayor's macro view, New York is firing on all cylinders, and that's why the prices, seeming to defy logic, or at least proportion, keep going up.
Indians have the least proportion of welfare dependence of the major immigrant groups and 29% have a graduate or professional degree.In this section For and against the foreign-born Weldless The naked truth The Alamo, again Mark Neumann, Republican hothead Chopping up America's power Adjutants or accountants?
CdO was left in the least proportion on cotton.
In real-life situation, a mixture always has a least proportion of every component.
The modifying agent with the least proportion of polysiloxane was used in subsequent experiments to illustrate the excellent passivation of polysiloxane.
Mathematics teachers had the least proportion to confirm the utility of such professional development and the most proportion in considering it not useful.
The categories of "Nuclear structure" (90, 0.35%), "Secondary metabolites biosynthesis, transport and catabolism"(519, 2.0%), "RNA processing and modification" (1,121,4.4%), and "Extracellular structures" (62, 0.24%) had the least proportions.
Ms Hardinge did not know what she would spend the prize money on "but at least a proportion of it may be spent on champagne".
Jon-Jon Goulian's eyes are beady and his head is small, at least in proportion to the rest of him.
We were not particularly wealthy people and £240,000 for us was a significant commitment and we firmly believed we were liable for at least a proportion of the professional fees which eventually came to over £7m.
The store appeared to be busy on a recent visit, but traffic through the airport is down, and merchants say that sales are down at least in proportion to traffic.
