Where is "UPPER ONE QUARTER BLOCK" letter in Unicode?

Question

In fact we have

U+2581  ▁   e2 96 81    LOWER ONE EIGHTH BLOCK  
U+2582  ▂   e2 96 82    LOWER ONE QUARTER BLOCK     
U+2583  ▃   e2 96 83    LOWER THREE EIGHTHS BLOCK   
U+2584  ▄   e2 96 84    LOWER HALF BLOCK    
U+2585  ▅   e2 96 85    LOWER FIVE EIGHTHS BLOCK    
U+2586  ▆   e2 96 86    LOWER THREE QUARTERS BLOCK  LOWER THREE QUARTER BLOCK
U+2587  ▇   e2 96 87    LOWER SEVEN EIGHTHS BLOCK   

But only

U+2580  ▀   e2 96 80    UPPER HALF BLOCK
U+2594  ▔   e2 96 94    UPPER ONE EIGHTH BLOCK

But I really need all symmetric letters.

The question is not "how do it right" but "why" the things such as they are.

P.S. If somebody knows "how" -- write it down too:)

Answer 1

The reason why there isn't a complete set of block drawing characters can be found in Chapter 22 of the Unicode standard:

The Block Elements block (U+2580..U+259F) contains another collection of graphic compatibility characters. [...] These elements were used to create crude graphic displays in terminals or in terminal modes on displays where bit-mapped graphics were unavailable.

The fractional fills do not form a logically complete set but are intended only for backward compatibility.

Because they are compatibility characters, their use is not encouraged.