Below is an instruction that describes a task. Write a response that appropriately completes the request.

### Instruction:
How much Standard Rank has a Name of 311 south wacker drive, and a Year larger than 1990?

### Inputs:
table_name: table, columns: ['Pinn. Rank', 'Std. Rank', 'Name', 'Pinnacle height ft (m)', 'Standard height ft (m)', 'Floors', 'Year']

### Response:
SELECT SUM Std. Rank FROM table WHERE Name = 311 south wacker drive AND Year > 1990