COUNTIF equivalent in DAX using mathematical operators

I'm trying to create a measure in PowerBI that will do the same thing as this Excel formula:

=COUNTIF(J2:J378,"<=7")/COUNT(J2:J378)

Basically, I have a column with values for the number of days of completion and I'm trying to calculate the percentage that were completed in 7 days or less.

The denominator works fine; it's the numerator of the formula that won't work.

I have this measure for the numerator: Tim7Days = COUNTAX('Timeliness Query','Timeliness Query'[R2CinDays]<=7), but it keeps ignoring the "<=7" and giving me a total count.

I tried adding in FILTER functionality like I've seen elsewhere on community posts, but it just gives me error messages about multiple columns and scalar values. All the samples I see match text rather than use greater than or less than.