Please answer the following question: When did Nine Inch Nails return to touring after its lead singer decided to cease touring with the band?  Answer the above question based on the context below:  Nine Inch Nails, an industrial rock band fronted by Trent Reznor, has toured all over the world since its creation in 1988. While Reznor—the only official member until adding Atticus Ross in 2016—controls its creative and musical direction in the studio, the touring band performs different arrangements of the songs. In addition to regular concerts, the band has performed in both supporting and headlining roles at festivals such as Woodstock '94, Lollapalooza 1991 and 2008, and many other one-off performances including the MTV Video Music Awards. Prior to their 2013 tour, the band had played 938 gigs.Nine Inch Nails' live performances contrast with its in-studio counterpart. Reznor writes and performs nearly all Nine Inch Nails studio material, with occasional instrumental and vocal contributions from others artists. However, Reznor has typically assembled groups of backing musicians to interpret songs for tours and other live performances. Keyboardist Alessandro Cortini said that "if you see the show and you're used to the CDs it's pretty clear that the studio entity is different from the live entity".The only constant member of the live band is Reznor.  Live Nine Inch Nails performances are typically accompanied by lighting, stage, and video projection effects. Since 1999, the visual design components of live shows have been curated by Reznor with Rob Sheridan. Three tours have been chronicled on live albums and tour documentaries. Critical and commercial response to Nine Inch Nails live performances has generally been positive. Critics have pointed to the concerts' aggressive on-stage dynamic and visual designs as high points. Reznor decided in 2008 to cease touring with the band after a 2009 farewell tour. The band resumed touring in 2013, with the group planning a set of concerts in the U.S. beginning September 28.
Answer:
2013