Thanks for the quick response. I got my sql table to your format now (just in case anyone finds this useful).
| Code:  | 
 {arijdatavisualizer type="bar" hideTable="true" width="400" height="400"} 
{arisqltable} 
    {arisqltablecolumns} 
      {arisqltablecolumn id="Jahr" alias="Jahr" headCellTag="td" cellTag="th"} 
      {arisqltablecolumn id="Anzahl" alias="Anzahl"} 
    {/arisqltablecolumns} 
    {arisqltablequery} 
	SELECT YEAR(birthdate) as Jahr, count(*) as Anzahl FROM joomla_contentbuilder_list_records statelinks, joomla_contentbuilder_list_states states, joomla_zp_waitinglist wlist  
	WHERE statelinks.state_id = states.id AND states.title = 'Aufgenommen' AND wlist.id = statelinks.record_id GROUP BY YEAR(birthdate); 
    {/arisqltablequery} 
{/arisqltable} 
{/arijdatavisualizer}
  | 
 
However, the style is a bit messed up (probably because my theme resets a lot of basic css). Is there any recommendation on how to proceed? Otherwise I'll have to go through each property to see what is messing up my graph.