The Scoville scale is a measurement of the pungency (spiciness or "heat") of chili peppers, as recorded in Scoville Heat Units (SHU), based on the concentration of capsaicinoids.
You can find a list with the concentration of menthol in plants given in ppm. Here is a list I found on https://www.naturalmedicinefacts.info/chemical/17003.html. This is a type of scale that is similar to the Scoville scale, although it doesn't use human sensation as one of the criteria.
Mentha pulegium
found in Shoot
max 478,000 ppm
Helianthus annuus
sunflower
found in Flower
max 310,000 ppm
Mentha arvensis var. piperascens
found in Leaf
max 24,385 ppm
Mentha x piperita subsp. nothosubsp. piperita
found in Leaf
max 20,000 ppm
Mentha spicata
spearmint
found in Leaf
max 15,000 ppm
Mentha aquatica
bergamot mint, eau-de-cologne mint, lemon mint, orange mint, water mint
found in Shoot, Leaf
max 3,570 ppm
Micromeria fruticosa
found in Leaf
max 3,030 ppm
Pycnanthemum virginianum
Virginia mountain-mint, Virginia-thyme, wild basil
found in Shoot
max 3,016 ppm
Pelargonium graveolens
rose geranium, rose-scent geranium
found in Plant
max 1,852 ppm
Satureja parvifolia
found in Shoot
max 1,010 ppm
Hedeoma pulegioides
American false pennyroyal, American pennyroyal
found in Plant, Pollen Or Spore
max 1,000 ppm
Pycnanthemum incanum
hoary mountain-mint
found in Shoot
max 798 ppm
Pycnanthemum pilosum
hairy mountain-mint
found in Flower, Leaf
max 700 ppm
Mentha longifolia
Biblical mint, horse mint, silver mint, wild mint
found in Shoot
max 620 ppm
Pycnanthemum tenuifolium
narrow-leaf mountain-mint
found in Shoot
max 620 ppm
Artemisia dracunculus
French tarragon, Russian tarragon, silky wormwood, tarragon, wild tarragon
found in Shoot
max 500 ppm
Pycnanthemum muticum
blunt mountain-mint, clustered mountain-mint
found in Shoot
max 450 ppm
Satureja grandiflora
greater calamint, large-flower calamint, mint-savory, showy calamint, showy-savory
found in Shoot
max 420 ppm
Sideritis scardica
found in Shoot
max 370 ppm
Calamintha nepeta
lesser calamint
found in Plant
max 290 ppm
Minthostachys mollis
found in Shoot
max 215 ppm
Pycnanthemum clinopodioides
found in Shoot
max 176 ppm
Pycnanthemum beadlei
found in Shoot
max 140 ppm
Micromeria fruticosa subsp. barbata
found in Shoot
max 105 ppm
Mentha x rotundifolia
found in Leaf
max 80 ppm
33475
Micromeria thymifolia
found in Leaf
max 45 ppm
Ocimum basilicum
basil, sweet basil
found in Essential Oil, Plant
max 32 ppm
Pycnanthemum montanum
found in Shoot
max 32 ppm
Juniperus communis
common juniper, dwarf juniper, juniper, malchangel, mountain juniper, prostrate juniper
found in Fruit
max 22 ppm
Elytrigia repens
couch grass, coutch, dog grass, quack grass, quick grass, scutch, twitch grass
found in Plant, Rhizome
max 20 ppm
Hedeoma drummondii
New Mexico pennyroyal
found in Plant
max 10 ppm
Acinos suaveolens
found in Shoot
max 3 ppm
Calamintha nepeta subsp. glandulosa
lesser calamint
found in Leaf
max 1 ppm
Rheum palmatum
Chinese rhubarb, ornamental rhubarb
found in Rhizome
max 1 ppm