Add Vertical Border Line to Discrete Axis in SGPLOT

[svh]

Hello,

I am trying to add a vertical border between bars for q1 and q2 so that the bars for q1 are set off from the other grouped bars. If my x-axis were continuous, I would just use the REFLINE statement, but how do I do this when my x-axis is discrete? I want the line to extend the length of the y-axis. Thank you!

data have;
input year $ var $ value lowerci upperci;
cards;
2018 q1 3.4 3.2 3.6
2019 q1 3.9 3.8 4.0
2018 q2 2.1 2.0 2.2
2019 q2 3.0 2.8 3.2
2018 q3 1.8 1.5 2.1
2019 q3 1.4 1.3	1.5
;
run;

proc sgplot data=have;
  vbarparm category=var response=value/  group=year limitlower=lowerci groupdisplay=cluster  limitupper=upperci barwidth=.6 tip=(value) ;
  yaxis min=0 max=4 minor values= (0 to 4 by .5) grid  label="Strongly disagree : Strongly agree";
  xaxis label = ' ';
  run;

[ballardw]

Not the slickest but:

proc format library=work;
value $q 
'q1.5' = ' '
other = [$2.]
;
run;

proc sgplot data=have;
  vbarparm category=var response=value/  group=year limitlower=lowerci groupdisplay=cluster  
                                       limitupper=upperci barwidth=.6 tip=(value);
  refline 'q1.5' /axis=x ;
  yaxis min=0 max=4 minor values= (0 to 4 by .5) grid  label="Strongly disagree : Strongly agree";
  xaxis label = ' ' values=('q1' 'q1.5' 'q2' 'q3') valuesformat=$q.;
run;