Selling, general, and administrative (SG&A) expenses as a percentage of revenue decreased from 13.2% in 2018 to 10.8% in 2019. What explanation does Tesla provide for this decrease? Does this explanation seem reasonable? Why or why not? How might this decrease (or underlying reasons for the decrease) affect the audit plan? Refer to at least one management assertions the auditor needs to consider related to the SG&A expenses.