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

### Instruction:
What was the total number of years than had best improved singer (躍進歌手)?

### Inputs:
table_name: table, columns: ['Year', 'Award', 'Category', 'Nomination', 'Result']

### Response:
SELECT SUM Year FROM table WHERE Category = best improved singer (躍進歌手)