| E | O (JD) | O (dat) | Period |
| -69 | 2419100 | 1911-03-04 | 334.7 |
| -53 | 2424540 | 1926-01-24 | 334.63 |
| -52 | 2424830 | 1926-11-10 | 334.6 |
| -43 | 2427850 | 1935-02-16 | 335.55 |
| -42 | 2428180 | 1936-01-12 | 334.11 |
| -41 | 2428513 | 1936-12-10 | 332.5 |
| -40 | 2428849 | 1937-11-11 | 333.41 |
| -39 | 2429175 | 1938-10-03 | 333.67 |
| -38 | 2429500 | 1939-08-24 | 334.93 |
| -37 | 2429845 | 1940-08-03 | 335.52 |
| -36 | 2430170 | 1941-06-24 | 335.74 |
| -19 | 2435870 | 1957-01-31 | 336.26 |
| -18 | 2436230 | 1958-01-26 | 336.61 |
| -17 | 2436566 | 1958-12-28 | 337.11 |
| -16 | 2436902 | 1959-11-29 | 338.93 |
| -15 | 2437241 | 1960-11-02 | 342.65 |
| -14 | 2437588 | 1961-10-15 | 341 |
| -13 | 2437934 | 1962-09-26 | 340.85 |
| -12 | 2438274 | 1963-09-01 | 341.28 |
| -11 | 2438623 | 1964-08-15 | 340.72 |
| -10 | 2438947 | 1965-07-05 | 340.15 |
| -9 | 2439293 | 1966-06-16 | 340.14 |
| -8 | 2439628 | 1967-05-17 | 339.35 |
| -7 | 2439971 | 1968-04-24 | 339.64 |
| -6 | 2440313 | 1969-04-01 | 340.29 |
| -5 | 2440657 | 1970-03-11 | 339.94 |
| -4 | 2440991 | 1971-02-08 | 340.43 |
| -3 | 2441334 | 1972-01-17 | 340.42 |
| -2 | 2441670 | 1972-12-18 | 340.35 |
| -1 | 2442010 | 1973-11-23 | 339.83 |
| 0 | 2442355 | 1974-11-03 | 339.13 |
| 1 | 2442695 | 1975-10-09 | 338.19 |
| 2 | 2443040 | 1976-09-18 | 337.5 |
| 7 | 2444725 | 1981-04-30 | 336.83 |
| 9 | 2445400 | 1983-03-06 | 335.47 |
| 13 | 2446735 | 1986-10-31 | 334.47 |
| 14 | 2447070 | 1987-10-01 | 333.89 |
| 15 | 2447400 | 1988-08-26 | 332.57 |
| 16 | 2447714 | 1989-07-06 | 330.79 |
| 17 | 2448055 | 1990-06-12 | 329.27 |
| 19 | 2448725 | 1992-04-12 | 327.22 |
| 20 | 2449049 | 1993-03-02 | 326.45 |
| 22 | 2449702 | 1994-12-15 | 328.39 |
| 23 | 2450030 | 1995-11-08 | 333.44 |
| 24 | 2450330 | 1996-09-03 | 335.61 |
| 25 | 2450660 | 1997-07-30 | 336.69 |
| 26 | 2451020 | 1998-07-25 | 337.23 |
| 42 | 2456430 | 2013-05-17 | 338.36 |
| 43 | 2456782 | 2014-05-04 | 339.25 |
| 44 | 2457120 | 2015-04-07 | 338.68 |
| 45 | 2457450 | 2016-03-02 | 338.38 |
| 46 | 2457798 | 2017-02-13 | 337 |
| 47 | 2458119 | 2017-12-31 | 335.92 |
| 48 | 2458463 | 2018-12-10 | 337.42 |
| 49 | 2458800 | 2019-11-12 | 337.01 |
| 50 | 2459130 | 2020-10-07 | 336.84 |
| 51 | 2459475 | 2021-09-17 | 338.33 |
| 52 | 2459819 | 2022-08-27 | 337.18 |
| E | Cycle number from the GCVS4 epoch. |
| O (JD) | Julian date at observed time for maximum. |
| O (Dat) | Same as above, expressed as date. |
| Period | Calculated mean period at cycle number E. |