Latvia was dependent on imports for raw materials. Limestone (for cement) and sand and gravel mines were spread throughout the country. Ceramic clays, dolomite, and gypsum also were produced. Peat (taken from 85 deposits, for fuel) covered approximately 10% of Latvia's territory, with the heaviest concentration in the eastern plains. Tonnage production figures for 2000 were: peat, 346,695, compared with 956,353 in 1999 and 171,700 in 1998; and sand and gravel, 440,914, compared with 787,317 in 1999 and 90,551 in 1997. Production figures for cement, gypsum, and limestone were withheld in 1999 and 2000 to avoid disclosing proprietary data.