
The year of manufacture can be determined by each instrument's serial number according to the table below.
|
Year |
First number |
Last number |
| 1977 | 1 | 29 |
| 1978 | 30 | 71 |
| 1979 | 72 | 100 |
| 1980 | 103 | 129 |
| 1981 | 130 | 156 |
| 1982 | 157 | 183 |
| 1983 | 184 | 207 |
| 1984 | 208 | 242 |
| 1985 | 243 | 270 |
| 1986 | 271 | 298 |
| 1987 | 299 | 330 |
| 1988 | 331 | 360 |
| 1989 | 361 | 388 |
| 1990 | 389 | 422 |
| 1991 | 423 | 451 |
| 1992 | 452 | 481 |
| 1993 | 482 | 508 |
| 1994 | 509 | 532 |
| 1995 | 533 | 560 |
| 1996 | 561 | 586 |
| 1997 | 587 | 607 |
| 1998 | 608 | 629 |
| 1999 | 630 | 647 |
| 2000 | 648 | 689 |
| 2001 | 690 | 713 |
| 2002 | 714 | 735 |
| 2003 | 736 | 753 |
| 2004 | 754 | 770 |
| 2005 | 771 | 784 |
| 2006 | 785 | 805 |
| 2007 | 806 | 820 |
| 2008 | 821 | 840 |
| 2009 | 841 | 857 |
| 2010 | 858 | 875 |
| 2011 | 876 | 892 |
| 2012 | 893 | 910 |
| 2013 | 911 | 922 |
| 2014 | 923 | 940 |
| 2015 | 941 | 961 |
| 2016 | 962 | 978 |
| 2017 | 979 | 991 |
| 2018 | 992 | 1007 |
| 2019 | 1008 | 1026 |
| 2020 | 1027 | 1048 |
| 2021 | 1049 | 1070 |
| 2022 | 1071 | 1091 |
| 2023 | 1092 | 1108 |
| 2024 | 1109 | 1121 |
| 2025 | 1122 | 1138 |
The number is stamped on the back of the head and in most cases behind the other joints as well.
The instruments all bear this mark: 