How to create multiple trend lines without clicking on each line in the graph

[ExcelNoob101]

I am trying to create a trendline for multiple series. Is there a way to "create trendline for all series"? I have also tried to use the linest function to get the trendlines but it does not work because I have gaps in my data. Below is an example of my data which I would like to create a polynomial degree 6 trendline for (or get the equation for the trendline). I know I could remove the gaps or add a trendline one by one, but I would like to find a faster way to do this because I will have a much bigger table than what I am providing for this example. Any help would be appreciated. I have spent quite a while trying to find this out on my own. I know this example data does not need polynomial degree 6, but the data that I am actually needing it for has about 250 Y values and does require a higher degree polynomial. Thanks in advance and here is a sample table:

Y Value	X1	X2	X3	X4
1		-64	-66	-63
2
3		-64		-64
4	-65		-63
5		-59
6	-68			-61
7	-61	-62	-57
8	-69	-57
9	-63		-54	-62

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