How to ret percentage per value

Hi everyone. Could you please help me with percentage calculation in LookML? 

I need to count percentage of yes and no answers per question.

I received 100% for Yes and for No as well. But I wish to have result like No - 43%, Yes - 57%

 

   
My code is 
 

Select distinct
  RespondentId,
  question_name,
  yes_no
From Survey_Responses
Where question_name in ('sec2_5')

  dimension: respondent_id {
    hidden: yes
    type: string
    sql: ${TABLE}.lRespondentID ;;
  }

  dimension: question_name {
    label: "Question Name"
    type: string
    sql: ${TABLE}.question_name;;
  }

  dimension: value {
    label: "Yes/No"
    type: string
    sql: ${TABLE}.yes_no;;
  }

  measure: yes_no_total {
    label: "Yes/No Total"
    type: number
    value_format: "#####"
    sql: Count(${value});;
  }

  measure: ratio_total {
    label: "% Ratio Yes/No"
    type: number
    value_format_name: percent_2
    sql: ${yes_no_total}/nullifzero(Count(${value}));;
  }