function calculateTailgateData(
  number_steps,
  opening_angle,
  
  tailgate_angle_v1,
  tailgate_angle_v2,
  tailgate_angle_v3,
  tailgate_angle_v4,
  tailgate_angle_v5,
  
  tailgate2_angle_v1,
  tailgate2_angle_v2,
  tailgate2_angle_v3,
  tailgate2_angle_v4,
  tailgate2_angle_v5,
  tailgate2_angle_v6,
  tailgate2_angle_v7,
  tailgate2_angle_v8,
  tailgate2_angle_v9,
  tailgate2_angle_v10,
  tailgate2_angle_v11,
  tailgate2_angle_v12,
  tailgate2_angle_v13,
  tailgate2_angle_v14,
  tailgate2_angle_v15 )
  
  local function fixFloatValue(val)
    if val == nil then
      val = 0.0
    end
    return val
  end
  
  local openingAngle = 0.0
  local trunkOpenMin = 0.0
  local trunkOpenMax = 0.0
  
  -- set min and max trunk opening values based on 5 or 15 step trunk version
  -- and choose proper angle value for current trunk state
  if number_steps == "step_5" then  
    trunkOpenMin = fixFloatValue(tailgate_angle_v1)
    trunkOpenMax = fixFloatValue(tailgate_angle_v5)
    
    if opening_angle < 1.5 then
      openingAngle = fixFloatValue(tailgate_angle_v1)
    elseif opening_angle < 2.5 then
      openingAngle = fixFloatValue(tailgate_angle_v2)
    elseif opening_angle < 3.5 then
      openingAngle = fixFloatValue(tailgate_angle_v3)
    elseif opening_angle < 4.5 then
      openingAngle = fixFloatValue(tailgate_angle_v4)
    else
      openingAngle = fixFloatValue(tailgate_angle_v5)
    end    
  else
    trunkOpenMin = fixFloatValue(tailgate2_angle_v1)
    trunkOpenMax = fixFloatValue(tailgate2_angle_v15)
    
    if opening_angle < 1.5 then
      openingAngle = fixFloatValue(tailgate2_angle_v1)
    elseif opening_angle < 2.5 then
      openingAngle = fixFloatValue(tailgate2_angle_v2)
    elseif opening_angle < 3.5 then
      openingAngle = fixFloatValue(tailgate2_angle_v3)
    elseif opening_angle < 4.5 then
      openingAngle = fixFloatValue(tailgate2_angle_v4)
    elseif opening_angle < 5.5 then
      openingAngle = fixFloatValue(tailgate2_angle_v5)
    elseif opening_angle < 6.5 then
      openingAngle = fixFloatValue(tailgate2_angle_v6)
    elseif opening_angle < 7.5 then
      openingAngle = fixFloatValue(tailgate2_angle_v7)
    elseif opening_angle < 8.5 then
      openingAngle = fixFloatValue(tailgate2_angle_v8)
    elseif opening_angle < 9.5 then
      openingAngle = fixFloatValue(tailgate2_angle_v9)
    elseif opening_angle < 10.5 then
      openingAngle = fixFloatValue(tailgate2_angle_v10)
    elseif opening_angle < 11.5 then
      openingAngle = fixFloatValue(tailgate2_angle_v11)
    elseif opening_angle < 12.5 then
      openingAngle = fixFloatValue(tailgate2_angle_v12)
    elseif opening_angle < 13.5 then
      openingAngle = fixFloatValue(tailgate2_angle_v13)
    elseif opening_angle < 14.5 then
      openingAngle = fixFloatValue(tailgate2_angle_v14)
    else
      openingAngle = fixFloatValue(tailgate2_angle_v15)
    end    
    
  end
  
  return openingAngle, trunkOpenMin, trunkOpenMax
end