pre_text: Results of Operations The following table sets forth, as a percentage of total revenues, the results from our operations for the periods indicated.
table: 2019 2018
table: Revenues 100.0% 100.0%
table: Cost of revenues 10.6 11.0
table: Gross profit 89.4 89.0
table: Operating expenses:
table: Sales and marketing 54.2 52.6
table: Product development 6.2 8.1
table: General and administrative 20.5 20.9
table: Total operating expenses 80.9 81.6
table: Income from operations 8.5 7.4
table: Other income (loss), net (0.5) —
table: Income before income taxes 8.0 7.4
table: Income tax expense 4.3 3.2
table: Net income 3.7% 4.2%
question: Analyse this data from a financial earnings document. What is the change in sales and marketing expenses between 2018 and 2019 as a percentage of total revenues?