convert Columns to rows

Question

I have data in below format in sql server 

 

YRC	a	b	c	d	e	f
201903	305.39	983	-95.71	-814.68	72.61	378
201803	198.56	693.93	-207.34	-379.77	106.83	305.39
201703	193.25	688	-342.1	-340.58	5.32	198.56

 

 

Need to convert in below format 

 

201903	201803	201703	Columnname
305.39	198.56	193.25	a
983	693.93	688	b
-95.71	-207.34	-342.1	c

 

 

Please help