A percentage is a pure number: it has no measurement units.
relative humidity
Your measurement should include one estimated digit.
4
4 of them.
Percentages are percentages - simple! The marketing people have not yet come up with "new improved" percentages.
Relative humidity is recorded in percentages.
relative humidity
relative humidity
data
The Egyptans did
cubit
Because it takes too long to spell out the value in words!
Your measurement should include one estimated digit.
4
4 of them.
4 of them.
the nearest .01 mL