REUTERS Natural gas stocks in Ukraine&#39;s underground storage facilities from May 12 to May 19 grew by 4.2%, or 362 million cubic meters (mcm), to 8.904 billion cubic meters (bcm) from 8.542 bcm. Some 60.14 mcm was pumped into the underground storage facilities on May 19 alone, the operator of the Ukrainian gas transport system, Ukrtransgaz, has said. As of today, 28% of the facilities are filled with natural gas, it said. Read alsoNatural gas stocks in Ukraine&#39;s underground facilities grow to 8.54 bcm As UNIAN reported earlier, Ukraine started 2018 with 14.7 bcm of gas in its underground storage facilities, which was the largest gas stock as of the beginning of the year in the past five years. On October 26, Ukraine stopped injecting gas into underground storage facilities and began pumping it out for the smooth heating season. On April 13, 2018, Ukrtransgaz stopped using gas from the underground storage facilities and started pumping 19-28 mcm of gas into the facilities on a daily basis.