<Table> <Tr> <Th_colspan="2"> National Day of Prayer </Th> </Tr> <Tr> <Th> Observed by </Th> <Td> United States </Td> </Tr> <Tr> <Th> Date </Th> <Td> First Thursday in May </Td> </Tr> <Tr> <Th> 2016 date </Th> <Td> May 5 (2016 - 05 - 05) </Td> </Tr> <Tr> <Th> 2017 date </Th> <Td> May 4 (2017 - 05 - 04) </Td> </Tr> <Tr> <Th> 2018 date </Th> <Td> May 3 (2018 - 05 - 03) </Td> </Tr> <Tr> <Th> 2019 date </Th> <Td> May 2 (2019 - 05 - 02) </Td> </Tr> <Tr> <Th> Frequency </Th> <Td> annual </Td> </Tr> <Tr> <Th> Related to </Th> <Td> Day of Prayer </Td> </Tr> </Table> <Tr> <Th_colspan="2"> National Day of Prayer </Th> </Tr>

When was the last time we had a national day of prayer
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