By Adriana Barrera MEXICO CITY: Proven oil and gas reserves in Mexico declined for a sixth consecutive year at the start of 2019, underlining the scale of the task facing the new government as it tries to revive output under ailing state oil firm Petroleos Mexicanos ( Pemex ).Compared with a year earlier, proven hydrocarbon reserves in Mexico fell by 6.9 percent to 7.9 billion barrels of crude oil equivalent (boe), data from Mexico's National Hydrocarbons Commission (CNH) showed on Friday.The decline was slightly less steep than in the previous year. But the decrease means that total reserves now stand at less than half of what they were in 2006, according to CNH data.The government of new president Andres Manuel Lopez Obrador has vowed to boost crude output by around 50 percent and turn around Pemex's fortunes during his six-year term.However, for the time being, much of the attention in financial markets has been focused on Pemex's financial debts. They totalled well over $100 billion at the end of last year, making it one of the most indebted oil firms in the world.Lopez Obrador told a regular news conference on Friday that Pemex was a "strong" company and had no shortage of funds.Most of Mexico's proven oil and gas reserves belong to Pemex. A relatively small amount have been discoveries made by private producers following a 2013-14 legislative overhaul that allowed them to operate fields on their own.Proven crude oil reserves fell by 6.2 percent from last year to 6.1 billion barrels, while gas reserves dipped some 3.7 percent to 9.7 trillion cubic feet, the CNH said.