Maryland. Advertising and promotion expense declined $125 thousand, or 17.1%, from the comparable period in 2019. This decrease was largely due to the impacts that COVID-19 pandemic had on marketing and sponsorship activities. Data processing costs increased $132 thousand or 40.8%, from the second quarter of 2019 as the result of increased loan processing activity from our mortgage division, combined with processing activity relating to PPP loans. Other expenses were down $463 thousand or 28.0%, from the comparable period in 2019. The decrease was the result of a litigation reserve that existed for the comparable period in 2019, related to the litigation that was settled and paid out early in 2020.
Balance Sheet Summary
As of June 30, 2020, total assets were $1.6 billion compared with $1.2 billion as of December 31, 2019 and $1.1 billion as of June 30, 2019. Total assets increased $429.1 million, or 37.3%, from December 31, 2019 and $523.2 million, or 49.5%, from June 30, 2019, primarily due to strong loan growth.
Total loans, excluding mortgage loans held-for-sale, grew $298.3 million, or 30.9%, to $1.3 billion as of June 30, 2020, from $964.7 million as of December 31, 2019 and $377.8 million or 42.7% from $885.2 as of June 30, 2019. The increase in loans for both periods is attributable largely to the $260 million in PPP granted to borrowers during the three months ended June 30, 2020. There was also growth in several commercial categories as we continue to grow our presence in the Philadelphia market area. Commercial real estate loans increased $54.1 million, or 14.5% from December 31, 2019, and $84.0 million, or 24.5% from June 30, 2019. Commercial loans increased $7.9 million, or 4.0%, from December 31, 2019, and $26.2 million, or 14.5% from June 30, 2019. Small business loans increased $9.3 million, or 42.8% from December 31, 2019, and $22.7 million, or 270.4% from June 30, 2019. Residential mortgage loans held for sale increased $84.0 million, or 249.2%, to $117.7 million as of June 30, 2020 from $33.7 million at December 31, 2019 and $78.4 million from $39.3 million as of June 30, 2019. The increase in mortgage originations is primarily the result of our expansion of our mortgage division into Maryland as well as the increase in refinance activity throughout all areas of our mortgage division.
Deposits were $1.2 billion as of June 30, 2020, up $315.5 million, or 37.1%, from December 31, 2019, and up $326.0 million, or 38.8%, from June 30, 2019. Non-interest bearing deposits increased $74.9 million, or 53.7%, from December 31, 2019 and increased $87.2 million, or 68.6%, from June 30, 2019. Interest-bearing checking accounts increased $118.2 million, or 125.2%, from December 31, 2019, and increased $124.5 million or 141.4% from June 30, 2019. Money market accounts/savings accounts increased $114.4 million, or 37.5% since December 31, 2019 and $135.2 million, or 47.5%, since June 30, 2019. Increase in core deposits were driven from PPP loan customers as well as new business and municipal relationships. Certificates of deposit increased $8.0 million, or 2.6%, from December 31, 2019 and decreased $21.0 million, or 6.2%, from June 30, 2019.
Consolidated stockholders’ equity of the Corporation was $125.5 million, or 7.95% of total assets as of June 30, 2020, as compared to $120.7 million, or 10.50% of total assets as of December 31, 2019. As of June 30, 2020, the Tier 1 leverage ratio was 8.06% for the Corporation and 10.71% for the Bank, the Tier 1 risk-based capital and common equity ratios were 10.24% for the Corporation and 13.60% for the Bank, and total risk-based capital was 14.91% for both the Corporation and Bank. Quarter-end numbers show a tangible common equity to tangible assets ratio of 7.68% for the Corporation and 10.15% for the Bank. A reconciliation of this non-GAAP measure is included in the Appendix. Tangible book value per share was $19.84 as of June 30, 2020, compared with $18.09 as of December 31, 2019.
Asset Quality Summary
Asset quality remains strong year-over-year. Meridian realized net charge-offs of 0.00% of total average loans for the quarter ending June 30, 2020, compared with net recoveries of 0.03% for the quarters ended December 31, 2019 and June 30, 2019. Total non-performing assets, including loans and other real estate property, were $7.5 million as of June 30, 2020, $3.4 million as of December 31, 2019, and $4.3 million as of June 30, 2019. The ratio of non-performing assets to total assets as of June 30, 2020 was 0.48% compared to 0.29% as of December 31, 2019 and 0.40% as of June 30, 2019. The ratio of allowance for loan losses to total loans held for investment, excluding loans at fair value and PPP loans (a non-GAAP measure), was 1.27% as of June 30, 2020, up from the 1.00% recorded as of December 31, 2019 and 0.99% as of June 30, 2019. PPP loans are excluded from calculation of this ratio as they are guaranteed by the SBA and