Single, Couple, Few, Several

Single: 1
Couple: 2
Few: 3-X
Several: Y-Z

Define X, Y, Z.
Is Y>X always true?

What do you think about how these terms are used? Does the meaning of the words change based on the context? For example, "I'll be there in a few minutes" always seems to be more than just three minutes; do I dare say five?

A few responses I have received:
"Few: 3

Several: 4 - many
Many: "I can't be bothered to count"

"several > few, therefore Y > X. QED
those ">" would mean "strictly greater than" in this context"

"M-W defines "several" as "more than two but not very many." Wiktionary defines several as "more than two or three," which I interpret to mean that Y can be either 3 or 4 (because otherwise it should be defined simply as "more than 3"). I think the range of "few" is highly dependent on the context in which it's used, whereas "several" is almost always single digits.
X: relative to the sample size (<10%).
Y: 3
Z: <10

Y>X is not always true."