Between 40-100 pages per hour is the average, but that's a wide range. I'd say about 50-60 pages per hour would be about average. If the topic of the literature is particularly dense/packed with information the number will move to the lower end of that range.
20 minutes is average.
It would take 3 minutes 6 seconds at that pace.
12 years = 144 months = about 626 weeks = about 4383 days on average = about 105,190 hours on average = about 6,311,390 minutes on average = 378,683,424 seconds on average (not counting leap seconds)
An average year is 365.25 days. I.e. 8766hrs or 525,960 mins, or 31,557,600 seconds
At an average 30 mph: 3 minutes, 12 seconds
6 minutes, 11 seconds
3 minutes and 32 seconds
There are 5 minutes and 50 seconds
7 minutes, 28 seconds
It is 3 minutes and 37 seconds
It is 11 minutes and 10 seconds
It is 2 minutes and 15 seconds