Certified GKH Gardening Expert
Depending on how young the plants are, you may not see any flowers in the first year of planting. Also, you should make sure they're getting enough sunlight, or you'll have less blooms. In addition, there may be too much nitrogen, which would cause lots of foliage and no blooms. Too little phosphorus can also result is little blooming activity.
Here is an article or two that you may find helpful: https://www.gardeningknowhow.com/ornamental/bulbs/snowdrop/information-about-snowdrops-and-when-to-plant-snowdrop-flower-bulbs.htm
https://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/phosphorus-plant-growth.htm