Twelve significant photographs in any one year is a good crop
This quote by Ansel Adams is used quite often, perhaps to motivate photographers who feel they aren't making enough good images. One image this month, a couple two months later, repeat over the years and this can become a significant body of work over time.
I have 2 problems with this approach, though.
First, it makes me feel lazy about my photography. What if it's mid-July and we already have 12 images we are proud of? I need and want to be pushed, it's the only way to improve.
Second, it symbolizes the "single image" photography. One unique, amazing exposure that everyone wants in their living room or as a wallpaper to wow people. I believe this isn't the right approach to build a consistent body of work.
You know what's better than 12 significant images a year? 12 projects containing 12 images each, less significant individual images but a much deeper and meaningful work.