I have a geotiff 16 bit multispectral data which converted to NDVI. Now I have about 30 polygons which are basically buffer strips on a stream and I want average, minimum and maximum NDVI value for each polygon. I used extract by mask tool and it works fine if I have a single polygon. It does not have an attribute table but I can still identify these values by changing the symbology to unique values. However, when I use a shapefile that has 30 different polygons, what I get is a data which shows me the mean, median, minimum and maximum of all the unique values of 30 polygons combined. What I want is 30 different numbers. The only way I know as of now is drawing 30 different shapefiles and then extracting each of them separately. Can someone suggest me a good way of doing this?