I am not realy sure but i do no the weight what is 45 pounds and 12 ounces i will try do find out for you what the groth is evry year

The classic response here is: It depends. There are two types of NP: Fast and slow growth. There are very obvious differences between them. Fast growth carry much more gurth and have an orange/red coloring on body and fins. Slow growth are mainly green and white and have a more narrow/sleek body. The other main factor is water temp. The more north you go slower growth and longer life. For example southern Canada to Northern Canada could vary by 2 fold. Southern NP mature 2x faster, they grow at twice the rate, but may only live half as long as Northern NP. I have been fishing the Gouin Resevoir for 20+ years. Givin it's location of 48degree 38'N and 74degree 45'W - I was able to research that a 40-42" fast growth NP is about 18-20 years old and a 36-38" slow growth (rare to catch that big at Gouin and in general) would be about 28-30 years. The Gouin has a shorter season, great food supply, but has seen a significant increase fishing pressure over the last 10 years. I have only found books that speak to growth rates of NP and Walleye - little comes up on-line. Look on Amazon for books on NP. Hope this helps a bit.