In 1986, computerized ticketing and reservations were introduced in New Delhi. In 1988, the first Shatabdi Express was introduced between New Delhi and Jhansi; it was later extended to Bhopal. Two years later, the first self-printing ticket machine (SPTM) was introduced in New Delhi. In 1993, air-conditioned three-tier coaches and a sleeper class (separate from second class) were introduced on IR. The CONCERT system of computerized reservations was deployed in New Delhi, Mumbai and Chennai in September 1996. In 1998, coupon validating machines (CVMs) were introduced at Mumbai Chhatrapati Shivaji Maharaj Terminus. The nationwide concierge system began operation on 18 April 1999. In February 2000, the Indian Railways website went online. On 3 August 2002, IR began online train reservations and ticketing. The Railway Budget was usually presented two days before the Union budget every year till 2016. The central government approved merger of the Rail and General budgets from next year, ending a 92-year-old practice of a separate budget for the nation's largest transporter. On 31 March 2017, Indian Railways announced that the country's entire rail network would be electrified by 2022 or 2023, and become a net-zero railway by 2030.