Answer:
80c to $1.20: up 50% or x 1.5
$1.20 to 80c: down 33 1/3 % or x 0.6 bar over the 6
80c to $1.60: up 100% or x 2
$1.60 to 80c: down 50% or x 0.5
$1.60 to $1.28: down 20% or x 0.8
$1.28 to $1.60: up 25% or x 1.25
$1.28 to $1.20: down 6 1/4 % or x 0.9375
$1.20 to $1.28: up 6 2/3 % or x 1.06 bar over the 6