Chart Data not updating when macro adds new line to data range for chart

I have a rainfall chart that has two columns of data A2 with Date and B2 with rainfall. I run a macro that copies the previous row A2 & B2 and inserts it above the previous row . The new row becomes 2 and the date is update to next day in A2 and B2 is cleared of previous data. This data in A2 to b2300 is added to a simple line chart but the data does not update after macro is run.
Thanks