Then I suspect it's a 4 year deal.
$70 million / 75% = $93 million or avg. $23 million a year.
If it's $75 million guarantee, I would think you move towards a 5 year deal.
$75 milllion / 75% = $100 million or an average of $20 million a year.
I'm guessing your numbers are very close and reality is between the two options above.
I use 75% because it seems like the guarantees are ranging around 75% of the total contract.
I'll say $22.5 million for 4 years with $70 million guaranteed. If it were 5 years, the guarantee would likely eclipse $80 million.