Pump efficiency

While browsing bicycle air pumps on an online store, I notice several models mentioning thier efficiency.
Examples: “*Efficiency: 168/122” , “*Efficiency: 28/19”

How is this measured? It obviously isn’t percent. I dunno if the “*” is just marking a footnote of if there is such a thing as “*Efficiency”

curious,

Brian

Further Googling indicates it is the number of strokes to fill a certain size tire to certain pressure. (Not sure what the size or pressure is, or if the 2 numbers mean different sizes and/or pressures)

Brian