| Date of Measurement | Apparent Muon Decay Time (Picoseconds) | Estimated Error (Picoseconds) | Muons at Rest or in high-speed Cosmic-ray generated Motion? | Reference |
| 1946.0 | 2,330,000 | ±150,000 | At Rest | Conversi, Pancini, Piccioni [3] |
| 1962.0 | 2,203,000 | ±4000 | At Rest | Lindy [6] |
| 1963.0 | 2,202,000 | ±3000 | At Rest | Eckhause, et al. [4] |
| 1973.0 | 2,197,300 | ±300 | At Rest | Duclos in Olive. [4] |
| 1974.0 | 2,197,110 | ±80 | At Rest | Balandin in Olive. [4] |
| 1984.0 | 2,196,950 | ±60 | At Rest | Giovanetti in Olive. [4] |
| 1984.0 | 2,197,078 | ±73 | At Rest | Bardin in Olive. [4] |
| 2007.0 | 2,197,013 | ±21 | At Rest | Chitwood in Olive. [4] |
| 2008.0 | 2,197,083 | ±32 | At Rest | Barczyk in Olive. [4] |
| 2008.5 | 2,197,030 | ± 40 | At Rest | Coan & Ye in Olive [4] |
| 2009.5 | 2,196,980.3 | ±2.2 | At Rest | Webber/MuLan [5] |
| 2013.0 | 2,196,980.3 | ±2 | At Rest; a copy of 2009.5 measurement | Tischchenko [7] |
| 2015.02 | 2,110,000 | ±70,000 | Fast, Cosmic Ray | Barazandeh [8] |
| 2015.02 | 2,165,000 | ±403,000 | Fast, Cosmic Ray | Barazandeh [8] |
| 2016.0 | 2,078,000 | ±11,000 | At Rest | Physics OpenLab [9] |
| 2017.0 | 2,080,000 | ± 11,000 | At Rest | Adams [10] |