a trivia about RMark

[marzolin]

For the dipper story in Appendix C to be more realistic, it would be convenient in a future version to start numbering the 'ch' in 1981 instead of 1980, in order to retrieve 1983 as 'the' year with major floods in spring which affected both the 1982-83 and 1983-84 survivals. Be that as it may I enjoy the use of R to avoid the typing of the PIM. Thanks
The dipper data provider.