1  2  3  4  5  6  7 <- shift by 0
   8  9 10 11 12 13 14 <- shift by 1
  15 16 17 18 19 20 21 <- shift by 2
  22 23 24 25 26 27 28 <- shift by 3
  29 30 31 32 33 34 35 <- shift by 4
  36 37 38 39 40 41 42 <- shift by 5
  43 44 45 46 47 48 49 <- shift by 6