What is the percentage change in the revenue from 2018 to 2019?
{"Revenue": {"JUN 2019 $000": 426, "JUN 2018 $000": 1208}, "Expenses": {"JUN 2019 $000": -1035, "JUN 2018 $000": -989}, "Operating income": {"JUN 2019 $000": -609, "JUN 2018 $000": 219}, "Interest revenue": {"JUN 2019 $000": 5, "JUN 2018 $000": 9}, "Impairment of other intangible assets": {"JUN 2019 $000": -603, "JUN 2018 $000": -16902}, "Profit/(loss) before tax from discontinued operations": {"JUN 2019 $000": -1207, "JUN 2018 $000": -16674}, "Tax benefit/(expense) related to current pre-tax loss": {"JUN 2019 $000": -1150, "JUN 2018 $000": -55}, "Post-tax profit/(loss) of  discontinued operations": {"JUN 2019 $000": -2357, "JUN 2018 $000": -16729}}
revenue_2019 = df["Revenue"]["JUN 2019 $000"]
revenue_2018 = df["Revenue"]["JUN 2018 $000"]
answer = (revenue_2019 - revenue_2018) / revenue_2018 * 100.0