. our financial objectives include diversifying our financing sources , optimizing the mix and maturity of our long-term debt , and reducing our working capital . at year-end 2018 , our long-term debt had a weighted average interest rate of 3.3 percent and a weighted average maturity of approximately 4.8 years . the ratio of our fixed-rate long-term debt to our total long-term debt was 0.7 to 1.0 at year-end 2018