How many boxes are there in between Black and Pink, if the box just kept below blue is yellow?

Read the following information carefully and answer the questions that follow: In a shop, 7 boxes of different colours are kept. They are – Pink, Red, Green, Blue, Yellow, White and Black. Each box has a number written on it from 1 to 7 but not necessarily in the same order. These boxes are arranged in a stack in ascending order with the lowest numbered box at the top. The number of boxes above Pink box is same as the number of boxes below the Yellow box. White is in box number 5. There are as many boxes above green as below it. Only three boxes are there in between Blue and Black. Red is kept below Pink.