Adding x-ticks to every graph within a 'by' set for a twoway line

[Jeremy Clyne]

Hello, I have a general question about graphs containing a 'by' set. I am attempting to show how unionization rates have declined by education level over the years. I have attached an image of my two way line graph, I want every level of education to contain an x-axis with the relevant years. Is there a method to make this happen? I cannot find anything in the help section pertaining to this topic, any help is appreciated. Thanks!

Relevant code:
collapse (mean) Union , by(Schooling survyear)
twoway line Union survyear, by(Schooling)

[Nick Cox]

Sounds like an extra option, say

xtic(1999/2017)

except that your graph implies that there wasn't a survey every year.

You may want to tune the label default to say

xla(2000(5)2015)

In general, start at

help axis options