caption: Percentage difference of thermally averaged collision strengths from our 72-term <PERSON>--<PERSON> calculation versus temperature in 104 K for the transition 1--5. Results are from <PERSON> (1994, solid black line), <PERSON> (1999, dashed line; dashed blue line online version), <PERSON> (2012, dotted line; dotted red line online version), and Mendoza & Bautista (2014, dash--dotted line; dash-dotted green line online version).